A SYSTEM OF MEDICINE OSLER &M9CRAE CONTRIBUTORS TO VOLUME VII BARKER, LEWELLYS F., M.D. BRAMWELL, EDWIN, M.B.. F.R.C.P. (Edin. and Lond.), F.R.S. (Edin.). BURR, CHARLES W., M.D. BUZZARD, E. FARQUHAR, M.D., F.R.C.P. (Lond.). COLLINS, JOSEPH, M.D. GUSHING, HARVEY, M.D. HOLMES, GORDON M., M.D., M.R.C.P. JELLIFFE, SMITH ELY, A.M., M.D., Ph.D. MCCARTHY, DANIEL j.f M.D. RUSSEL, COLIN K., M.D. SACHS, BERNARD, M.D. % SOUTHARD, E. E., A.M., M.D. SPILLER, WILLIAM G., M.D. SPRATLING, WILLIAM P., M.D. . TAYLOR, EDWARD W., M.D. THOMAS, HENRY M., A.M., M.D. THE OXFORD MEDICAL PUBLICATIONS A SYSTEM OF MEDICINE BY EMINENT AUTHORITIES IN GREAT BRITAIN, THE UNITED STATES AND THE CONTINENT EDITED BY WILLIAM OSLER, M.D., F.R.S. REGIUS PROFESSOR OF MEDICINE IN OXFORD UNIVERSITY, ENGLAND; HONORARY PROFESSOR OF MEDICINE IN THE JOHNS HOPKINS UNIVERSITY, BALTIMORE; FORMERLY PROFESSOR OF CLINICAL MED1CINF IN THE UNIVERSITY OF PENNSYLVANIA, PHILADELPHIA, AND OF THE INSTITUTES OF MEDICINE IN MCGILL UNIVERSITY, MONTREAL, CANADA ASSISTED BY THOMAS MCCRAE, M.D., F.R.C.P. (Lond.) ASSOCIATE PROFESSOR OF MEDICINE AND CLINICAL THERAPEUTICS IN THE JOHNS HOPKINS UNIVERSITY, BALTIMORE, FELLOW OF THE ROYAL COLLEGE OF PHYSICIANS, LONDON. VOLUME VII. DISEASES OF THE NERVOUS SYSTEM LONDON HENRY FROWDE HODDER & STOUGHTON OXFORD UNIVERSITY PRESS WARWICK SQUARE. E.G. I9IO £$ ' Entered according to the Act of Congress in the year 1910, by LEA & FEBIGER in the office of the Librarian of Congress. All rights reserved. CONTRIBUTORS TO VOLUME YIL LEWELLYS F. BARKER, M.D., Professor of Medicine in the Johns Hopkins University; Physician-in-Chief to the Johns Hopkins Hospital, Baltimore, Md. EDWIN BRAMWELL, M.B., F.R.C.P. (EoiN. AND LOND.), F.R.S. (EoiN.), Assistant Physician to the Leith Hospital ; University Tutor in Clinical Medicine in the Royal Infirmary, Edinburgh, Scotland. CHARLES W. BURR, M.D., Professor of Mental Diseases in the Medical Department of the University of Pennsylvania, Philadelphia. E. FARQUHAR BUZZARD, M.D., F.R.C.P. (LOND.), Assistant Physician to the National Hospital for Paralyzed and Epileptic and to the Royal Free Hospital, London, England. JOSEPH COLLINS, M.D., Professor of Neurology in the Post-Graduate Medical School, New York. HARVEY GUSHING, M.D., Associate Professor of Surgery in the Johns Hopkins University, Baltimore, Md. GORDON M. HOLMES, M.D., M.R.C.P., Director of the Nervous Disease Research Fund, National Hospital, London, England. SMITH ELY JELLIFFE, A.M., M.D.,- PH.D., Clinical Assistant in the Department of Neurology in Columbia University; Visiting Neurologist to the City Hospital; Consulting Neurologist to the Manhattan State Hospital, New York. DANIEL j. MCCARTHY, M.D., Professor of Medical Jurisprudence in the Medical Department of the Uni- versity of Pennsylvania; Neurologist to the Henry Phipps Institute and to the Philadelphia and St. Agnes Hospitals, Philadelphia. COLIN K. RUSSEL, M.D., Demonstrator of Clinical Medicine in McGill University, Montreal, Canada. BERNARD SACHS, M.D., Alienist and Neurologist to Belle vue Hospital; Neurologist to the Mt. Sinai Hospital; Consulting Physician to the Manhattan State Hospital, New York. E. E. SOUTHARD, A.M., M.D., Bullard Professor of Neuropathology in the Medical School of Harvard Uni- versity, Boston, Massachusetts; Pathologist to the State Board of Insanity, Massachusetts ; Formerly Pathologist and Assistant Physician to the Danvers State Hospital, Hathorne, Massachusetts. (v) vi CONTRIBUTORS TO VOLUME VII WILLIAM G. SPILLER, M.D., Professor of Neuropathology and Associate Professor of Neurology in the Medical Department of the University of Pennsylvania, Philadelphia. WILLIAM P. SPRATLING, M.D., Professor of Nervous Diseases in the College of Physicians and Surgeons, Balti- more; formerly Medical Superintendent of the Craig Colony for Epileptics, Sonyea, New York. EDWARD W. TAYLOR, M.D., Instructor of Neurology in the Medical School of Harvard University, Boston, Mass. HENRY M. THOMAS, A.M., M.D., Clinical Professor of Neurology in the Johns Hopkins University; Neurologist to the Johns Hopkins Hospital and Dispensary, Baltimore, Md. CONTENTS OF VOLUME VII. DISEASES OF THE NERVOUS SYSTEM. CHAPTER I. INTRODUCTION TO DISEASES OF THE NERVOUS SYSTEM ... 17 BY LEWELLYS F. BARKER, M.D. CHAPTER II. DISEASES OF THE MOTOR TRACTS . . 82 BY WILLIAM G. SPILLER, M.D. CHAPTER III. COMBINED SYSTEM DISEASES OF THE SPINAL CORD .... 126 BY COLIN K. RUSSEL, M.D. CHAPTER IV. SCLEROSES OF THE BRAIN 142 BY EDWIN BRAMWELL, M.B., F.R.C.P. (EoiN. AND LOND.), F.R.S. (EoiN.) CHAPTER V. DISEASES OF THE MENINGES 164 BY EDWIN BRAMWELL, M.B., F.R.C.P. (LOND. AND EDIN.) CHAPTER VI. DIFFUSE AND FOCAL DISEASES OF THE SPINAL CORD ... 181 BY E. FARQUHAR BUZZARD, M.D., F.R.C.P. (LOND.) CHAPTER VII. TOPICAL DIAGNOSIS OF DISEASE OF THE BRAIN 279 BY JOSEPH COLLINS, M.D. CHAPTER VIII. APHASIA 308 BY JOSEPH COLLINS, M.D. CHAPTER IX. DISEASES OF THE CEREBRAL BLOODVESSELS 327 BY HENRY M. THOMAS, A.M., M.D. CHAPTER X. TUMORS OF THE BRAIN AND MENINGES 418 BY HARVEY GUSHING, M.D. (vii) vji| CONTENTS OF VOLUME VII CHAPTER XL HYDROCEPHALUS 459 BY HARVEY GUSHING, M.D. CHAPTER XII. DISEASES OF THE PERIPHERAL NERVES 467 BY GORDON M. HOLMES, M.D., M.R.C.P. CHAPTER XIII. DISEASES OF THE CEREBRAL NERVES 524 BY E. W. TAYLOR, M.D. CHAPTER XIV. PARALYSIS AGITANS. CHOREA. CHOREIFORM AFFECTIONS. INFANTILE CONVULSIONS 588 BY DANIEL J. MCCARTHY, M.D. CHAPTER XV. ACUTE ENCEPHALITIS AND BRAIN ABSCESS 624 BY E. E. SOUTHARD, M.D. CHAPTER XVI. EPILEPSY 654 BY WILLIAM P. SPRATLING, M.D. CHAPTER XVII. SYPHILITIC AND PARASYPHILITIC DISEASES OF THE CENTRAL NERVOUS SYSTEM . . 682 BY BERNARD SACHS, M.D. CHAPTER XVIII. NEURASTHENIA. THE TRAUMATIC NEUROSES AND PSYCHO- SES ' - . 721 BY CHARLES W. BURR, M.D. CHAPTER XIX. MIGRAINE. NEURALGIA. PROFESSIONAL SPASMS. OCCUPA- TION NEUROSES. TETANY 750 BY SMITH ELY JELLIFFE, A.M., M.D., PH.D. CHAPTER XX. HYSTERIA 811 BY SMITH ELY JELLIFFE, A.M., M.D., PH.D. CHAPTER XXI. AMAUROTIC FAMILY IDIOCY (TAY-SACHS DISEASE) 868 BY BERNARD SACHS, M.D. DISEASES OF THE NERVOUS SYSTEM. CHAPTER I. INTRODUCTION TO DISEASES OF THE NERVOUS SYSTEM. By LEWELLYS F. BARKER, M.D. THE SENSES AND THEIR SYMPTOMATOLOGY. IT is convenient to divide the senses into two groups, interior and exterior. The interior senses are those of which we project the sensations, into some part of our own bodies. They include pain, movement sense, position sense, resistance sense, the vestibular sense, hunger, thirst, the sexual sense, and the sense of fatigue. The exterior senses are those of which we project the sensations into the world outside ou*Selves. They include sight, hearing, taste, smell, touch and pressure, and the two temperature senses, heat and cold. The Interior Senses. — Pain. — Physiologists now regard this as a special sense, and not simply as a negative feeling tone associated with overstimula- tion of other sense organs (von Frey). This pain sense has a punctiform distribution in the skin. As tested by very fine needles, the points are more numerous even than the touch points. The strength of the stimulus required to call forth a sense of pain is called the threshold stimulus, and this varies for different pain points. The localization of pain sensations is due less to the pain nerves than to the simultaneous stimulation of the sense of touch. Visceral pain is often not localized in the viscera themselves, but is referred to certain areas in the skin (Head). The cutaneous hypersesthesias in car- diac, gastric, intestinal, and prostatic diseases are examples of such mis- reference. The pain sense of the skin and viscera has been designated by Head and Rivers as protopathic sensibility, in contrast with touch and tem- perature senses, which they call epicritic sensibility. Sometimes the peripheral nerves are oversensitive to pressure, particularly at places where they emerge from bony openings (I'alleix's poiniff). Deep or Mesoblastic Sensibility (Sensations from Muscles, Bones, Joints, and Fasciae). Sensations of Movement of Parts of the Body; of Their Position, and of Resistance. Bathyaesthesia. — Under the term "muscle sense," a whole series of different sensations have been roughly lumped together. This is due largely to the lack of sharpness of these sensations in consciousness. We VOL. vii. — 2 ( 17 ) 18 DISEASES OF THE NERVOUS SYSTEM must distinguish at least the following: (1) The sense of position of the individual parts of the body; (2) the sense of movements of these parts; (3) sensations of resistance and weight; (4) the stereognostic sense; (5) the so-called vibration sense (pallsesthesia) . 1. Sense of Position of Individual Parts of the Body. — The normal person is able actively to imitate with one-half of his body positions in which portions of the other half are passively placed. 2. Sense of Movement of Individual Parts of the Body. — When the eyes are closed and active or passive movements of a part of the body are made, a normal person is able to state (a) that a movement has occurred, (6) the degree of this movement, and (c) its direction. This sense of movement differs from the sense of position. In normal individuals any movement that the examiner himself can see should be recognized. When a joint has to be flexed or extended through several degrees before a sensation is detected, the movement sense is subacute. It should be remembered that smaller movements can be recognized in the shoulder and wrist than in the knee, hip, or elbow. The ankle-joint and the joints of the ringers and toes are still less sensitive. In right-handed individuals the movement sense is more delicate on the right side than on the left. 3. Sensations of Resistance and Weight. — The sense of weight is not iden- tical with that of resistance and is more delicate in the upper than in the lower extremities. 4. Stereognostic Sense, or Perception. — The capacity to recognize the form and consistence of objects by touching and feeling them is known as stere- ognosis. One places in the hand of the blindfolded patient blocks of various shapes or familiar objects, such as knives, keys, and coins, and asks him to describe their form and consistence and to name them. This capacity involves the combined activities of the movement sense, resistance sense, position sense, sense of touch, and sense of temperature. Even more, certain higher cortical faculties are involved, including the spatial and temporal arrange- ment of the sense impressions and the memory pictures of previous sensa- tions. Obviously, we have to do here not simply with sensation, but with a combination of sensory, associative, and reproductive processes. 5. Vibration Sense, or Palloesthesia. — Rapidly vibrating objects when placed upon the skin over a bone yield a peculiar vibrating sensation known as pallsesthesia. Clinically, one examines the sensation best by placing the handle of a vibrating tuning-fork of 64 or 128 oscillations per second firmly upon the surface of the skin over one of the bones. Vestibular and Allied Senses. Sense of Static Equilibrium. Sensations of Position of the Body as a Whole. Sensations of Movement of the Body as a Whole (Rotary and Non-rotary or Progressive). Sensations of Orientation in Terrestrial Space. Sensibility to Accelerations in a Straight Line and to Angular Accelerations. — Here wre have to deal with a great group of centripetal impulses which are of high importance for the functions of equilibrium, locomotion, and orientation. It seems likely that most of the centripetal impulses concerned are infraconscious, or that their psychic correlate is relatively insignificant. The directions up and down are recognized by everybody, though how the force of gravity is made known to us is not clear. Even under water the capacity for orientation as to the vertical direction is unimpaired. The mechanism, whatever it is, is sensitive to accelerations in a straight line, and THE SENSES AND THEIR SYMPTOMATOLOGY 19 gives rise not only to our knowledge of the vertical direction, but also to sen- sations of progressive or non-rotary movements. In addition to this mechan- ism, there is another apparatus in the head which is sensitive to angular accelerations and gives us sensations of change of velocity of rotary move- ments. These sensations, which follow accelerations in a straight line and angular accelerations, are associated with characteristic eye-muscle reflexes. An alteration of the position of the head relative to the vertical causes a compensatory change in the setting of the eyeballs, and if the body be rotated around its vertical axis the eyes show movements of nystagmus as long as the sensations of rotation are felt. These sensations are connected with the functions of the membranous labyrinth of the internal ear. It seems probable that the information which the brain receives regarding the position of the head when it is at rest and regarding the acceleration or retardation of progressive (non-rotary) move- ments depends upon the nerve endings in the utricle and saccule, upon the maculae of which the little ear-stones or otoconia rest (Breuer), while the sense organ underlying the sensations dependent upon angular accelerations appears to be situated in the ampullary crests of the membranous ampullae of the semicircular ducts. While both the utricle and saccule, on the one hand, and the semicircular ducts, on the other, appear to have to do with static as well as dynamic sensations, it seems probable that the static are mediated rather more by the former, the dynamic rather more by the latter. The loss of orientation as to the vertical when under water and the absence of vertigo on rotation so often seen in deaf mutes are thought to be due either to imperfection of the otoconic apparatus or of the semicircular ducts. Other Interior Senses.— Hunger.— In its mild form this sensation is familiar to everyone as the appetite for food localized in the gastric region. The hunger sense is to some extent dependent upon metabolism. The well- known increase of appetite after muscular exertion, after exposure to cold, and in diabetes mellitus makes this clear. On fasting, the sense of hunger soon disappears, in marked contrast with the sense of thirst. Thirst. — The sense of thirst is referred to the back of the throat, and if no water be taken the sensations become painful. The sufferings of fasting patients are due to thirst rather than to hunger. Sense of Fatigue. — If the muscles are made to contract beyond a certain point, a feeling of fatigue is encountered. Whether this is due to centripetal impulses arising in the muscles themselves or to a change in the nerve centres in the cerebral cortex is not certain. Sexual Sense. — The impulse to sexual gratification is technically known as libido. The sexual impulse of adults appears to be'a unification of various childhood impulses; these culminate normally in an effort toward a single specific goal. Originally auto-erotic, the impulses become later hetero-erotic. The Exterior Senses. — Touch or Pressure. — The skin contains sensory mechanisms that permit us to recognize very slight contact and very light degrees of pressure. The sense organs are closely related to the hairs in parts of the body which possess these and to Meissner's corpuscles in other parts. When delicate stimuli are employed it is found that sensations are set up only when definite points are pressed upon. These are the so-called touch points of von Frey. They are much more numerous than cold points and warm points, but are less numerous than pain points. They are very numerous on 20 DISEASES OF THE NERVOUS SYSTEM the lips, tongue, and finger tips, and are relatively much scantier on the leg and upper arm. The stimuli do not act upon the sense organs directly, but rather indirectly through the skin surface or its hairs, producing deformations of the skin and thus causing alterations of pressure tensions or traction tensions in the tissue. The stimulus in reality is a function of the tension difference from place to place. To use a physical expression, the excitation depends upon the "pressure fall" and not on the pressure itself. Touch sensations following brief stimuli last only a short time, and if stimuli be repeated rapidly one receives a corresponding number of sensa- tions without fusion in consciousness. The threshold stimulus for individual touch points varies. One can determine the threshold most easily by the use of von Frey's test hairs. No marked feeling tone accompanies touch sensations, a fact which dis- tinguishes them1 sharply from sensations of pain. The time elapsing from the moment of application of the stimulus to a touch organ to the moment of appearance of sensation in consciousness is shorter for touch than for tem- perature or pain (reaction time). Touch sensations can be very accurately localized upon the surface of the body; indeed, the sense of touch, together with sight and movement sense, has done most to give to man his conceptions of spatial relations. Each touch point on the surface of the body seems to have its own "local sign;" that is, the sensation from it can be distinguished from that from every other. If two touch points are close together, however, they must be stimulated successively and not simultaneously if the two sepa- rate sensations are to be recognized (successive threshold of von Frey). When touch points are a certain distance apart, stimulation of them simultaneously gives rise to two separate sensations (simultaneous duplicity threshold of von Frey; space threshold of Weber). Tickling and Itching. — These are as yet not well understood. Tickling is probably to be separated physiologically from itching. However, both are closely related to touch sense and pain sense. It is possible that they should be regarded as secondary sensations rather than primary (H. Quincke), and that they are associated with vasomotor reflexes. It is interesting that the sensations are aroused by slight stimuli and can often be inhibited by more powerful stimulation in the same areas. The Temperature Sense. — In the skin and mucous membranes there are at least three varieties of sensory nerve beginnings which respond to thermal stimuli ; they are connected with the so-called cold points, warm points, and pain points. The adequate stimulus for a cold point is cold, that for a warm point is warmth, but both sets of points react to various disparate stimuli also; thus, one gets a sensation of cold when he stimulates a cold point by a sharpened stick, by the application of menthol, or by an electrical current, and a warm point can be stimulated not only by heat, but by mechani- cal irritation with fur, by exposure to carbon dioxide, or by electricity. Pain points are stimulated by cold below a certain temperature or by heat above a certain temperature. Touch points appear to be uninfluenced by thermal stimuli. The cold points are far more numerous than the warm points, but they are less evenly distributed than are the touch points and the pain points. Natural stimuli, as a rule, affect areas of the skin which contain a number of sensory points, so that our ordinary cutaneous sensations are complexes made up of a number and variety of elementary sensations. When the ther- THE SENSES AND THEIR SYMPTOMATOLOGY 21 mal stimulus corresponds in temperature to that of the skin no sensation at all is felt; if it correspond to a temperature slightly lower than that of the skin, the cold points alone respond and a sensation of coolness results; if it correspond to a temperature a little above that of the skin, a sensation of warmth is felt. Very low temperatures affect both the pain points and the cold points; very high temperatures may affect the warm points, the cold points, and the pain points simultaneously, and yield a mixed sensation com- pounded of warmth, cold, and pain, usually designated "burning hot." A word must be said about the power of adaptation of the skin to various external temperatures. The skin soon adjusts itself to objects of constant temperature applied to it, and on their removal a new thermal stimulus must have a temperature a quarter of a degree above or below that of the object previously applied if sensations of warmth or cold are to be experienced, owing to the so-called indifference zone (physiological zero), through which no sensations are excited. The position of this indifference zone varies with the external temperature and with the blood supply, and this explains why it is that there is often a lack of correspondence between the physiological temperature descriptions and the readings which we meet on the scale of a physical thermometer. The clinical methods for testing the temperature sense are very crude compared with our physiological knowledge of these senses. More accurate studies have been made in certain instances, and in some cases the threshold stimuli have been determined.1 A thermaesthesiometer has been introduced by Eulenburg, but has been but little used. Taste. — There are four simple elementary taste qualities: sour, sweet, salty, and bitter. All other so called taste sensations are either combinations of these, or are mixtures of taste sensations with sensations of smell, touch, temperature, or pain. Some taste sensations are associated with pleasurable feeling tone, others with negative feeling tone. Substances which can be tasted are known as "sapid substances," and are soluble in water or in saliva. They are crystalloid in nature, colloids being devoid of taste. Apparently there are entirely different sense organs for sour, sweet, salty, and bitter sensations. The adequate stimulus for arousing sour sensations appears to be the hydrogen ion of acids. No common chemical character has as yet been ascribed to the sapid substances which arouse sweet sensations; salty sensations, are best aroused by a 2 per cent, solution of sodium chloride, though various other salts can stimulate the sense organ concerned. Bitter sensations are aroused by very different chemical substances. Many of the alkaloids (strychnine) are bitter, but numerous sapid substances are bitter which are chemically unrelated to these (e. g., magnesium sulphate). The taste organs thus acted upon by chemical stimuli do not respond to mechan- ical or thermal stimuli. They do, however, sometimes respond to electric currents (so-called electric taste). Single taste modalities are variably represented in various parts of the tongue; thus, sweet taste is best represented at the tip, salty at the tip and margins, sour at the margins, and bitter at the posterior part of the dorsum lingua?. The centripetal nerves of taste leave the tongue by way of the lingual branch of the trigeminal nerve and by way of the glossopharyngeal nerve. The few taste buds of the larynx belong to the pneumogastric nerve. 1 Barker, Dentsrlies Arch. f. Nerrenheilk., 1898, viii, 348. 22 D/.s'/-:.t,s7->; OF TIII-; Threshold determinations in taste sensation have as yet been very little used, although the boite gustatometric/nc of Toulouse and Vast-hide and the sapid wedges of Zwaardemaker may be found useful. Smell. — This is closely related to taste sense, and naive observers often confound sensations of smell with those of taste. The nose possesses touch sense, temperature sense, and pain sense; when we inhale formalin, it is the pain sense which is chiefly aroused, and when we inhale menthol the tem- perature sense is also affected. Aside from distinguishing sensations of smell proper from other modalities of sensation, we have the still greater difficulty of analyzing olfactory sensations among themselves and resolving them into their simpler psychological constituents. The olfactory sensations are mediated by the neuro-epithelial cells in the olfactory region high up in the nose. The only approach to this olfactory area is through the narrow olfactory sulcus, so that the application of localized stimuli is fraught with extreme difficulty. The chemical substances brought to the olfactory area by air currents probably dissolve in the film of fluid which bathes the neuro-epithelium. Smell is to be regarded as a chemical sense, and the adequate stimuli are chemical substances which act directly upon the peripheral olfactory neu- rones. Other forms of stimuli seldom call forth an olfactory response, although certain smell sensations have been produced by electrical stimu- lation. Very minute amounts of certain chemical substances are sufficient to stimulate the sense organ, and they must be gaseous or volatile in order that they may mix with the air that enters the cavity of the nose. For human beings the smell sensations aroused by the entrance of chemical substances through the nasopharynx are more important than those dependent upon substances entering through the front of the nose. While there are only four fundamental varieties of taste sensations, it seems likely that there are, at least, twenty or thirty elementary olfactory sensations; the difficulties surrounding experimental investigation prevent any dogmatic statement concerning this number. Attempts at quantitative methods of examination of the sense of smell have been made, especially by Zwaardemaker. The term olfactometry has been applied to the measurement of the sensibility of the olfactory organ for adequate stimuli, and the term odorimetry is used to indicate the making of comparative measurements of the stimulating action of different sub- stances. We know nothing of exact localization of olfactory sensations. The olfac- tory sense is not easily fatigued, although it varies in this regard in its differ- ent modalities. The close relation of the olfactory sense to various reflex, instinctive, and affective phenomena need only be mentioned to be appre- ciated. The odor of food excites the impulse to eat and starts the secretion of gastric juice. The relation of the sense of smell to the excitation of the sexual impulses is well known, and the relation of odors to various affective states is close. The mood may be changed in a moment by a scent or a stink. The clinical examination of the sense of smell is usually carried out by holding odoriferous substances before one nostril at a time; the patient inhales and tries to name the substance. Well-known substances, chiefly, are used. As the majority of people are surprisingly inaccurate in the dis- crimination of smell sensations, the following series can be recommended: THE SENSES AND THEIR SYMPTOMATOLOGY 23 Rubber, gutta-percha, ether, yellow beeswax, camphor, oil of anise, vanilla, musk, asafoetida, cacodyl or ammonium sulphide, roasted coffee, pyridin, tar or carbolic acid, cheese or mutton tallow, tincture of valerian, skatol. Where smell is defective a careful examination of the nose should be made to make sure that the defect is not due to obstruction of the air currents in the nose rather than to any disturbance of the nervous mechanism itself. In addition to trying the olfactory sense, one may, if he likes, test the functions of the trigeminus in the nasal mucosa with the fumes of acetic acid, ammonia, formalin, and menthol. Hearing. — The organ of hearing mediates the sensations of sound. Sounds are divided into two great groups known as musical sounds and noises. The former are smooth, steady, and the latter rough, unsteady, or restless. Both are made up of elements known as tones, and all sounds in nature repre- sent combinations of several or many different tones. In compound sounds one simple tone is often dominant. This is the so-called fundamental tone. The associated higher tones are known as overtones. The compounds of tones which are musical are known as clangs, and the musical ear can dis- tinguish among the partial tones of a clang not only the fundamental tone, but also the various overtones. On looking for the adequate stimulus for the organ of hearing, it is found to consist of vibrations of varying periodicity, and the sensory nerve beginnings seem to be attuned to definite frequencies of vibration. The vibrations reach the organ of Corti either by air conduction through the external and middle ear or by osteotympanal conduction, the transmission occurring then through the bones of the skull. The organ of hearing is attuned to certain periodic movements only; thus, oscillations less frequent than 16 per second or more frequent than 50,000 per second fail to stimulate the ear. Sounds are ordinarily heard with both ears (diotic hearing), though some- times with one alone (monotic hearing). If a tuning-fork (a') be placed on the mastoid, the sound is heard by osteotympanal conduction. If at the moment when the sound ceases the fork be removed from the mastoid and placed before the ear, the tone can again be heard through air conduction (Rinne's experiment). Auditory sensations are projected into the external world, but man's power of localizing them is not very great. Although he can tell, when his ears are normal, whether a sound is more to his left than to his right, he is often in error when attempting to say whether a sound comes from below or above or from in front or behind. If a vibrating fork be placed in the median line of the head, exciting the two ears equally, and then one ear be loosely closed with the palm of the hand, the sound is markedly intensified in the closed ear — so-called lateralization of the sound (Weber's experiment). Quantitative measurements of hearing capacity are best carried out by using simple tones as stimuli. In order that two forks with vibration num- bers close to one another may give rise to tones which are distinguishable by the ear, there must be a certain difference in the number of vibrations (difference threshold for pitch). For a good musical ear the difference amounts to about half a vibration per second in the most favorable part of the scale. For poorer ears the vibration numbers must stand in relation to one another as 5 to 6, or even as 2 to 3. In otiatric diagnosis it is often im- portant to determine the upper and lower limits of audible tones. The best apparatus for this is the "continuous tone series" of Bezold-Edelmann, 24 DISEASES OF THE NERVOUS SYSTEM which permits of stimulating with vibrations numbering from 16 to 48,000 per second. The intensity threshold of a tone must also sometimes be studied ; that is, the intensity which a given tone must have in order to be just perceptible by the ear. Furthermore, a tone must continue for a certain length of time if tone sensation is to be aroused (duration threshold). Clinical Examination of the Sense of Hearing. — Ordinarily clinicians are satisfied with (1) determining the so-called auditory acuity; (2) testing the upper and lower tone limits; (3) Rinne's test; (4) Schwabach's test; (5) Weber's test; (6) Gelle's test. To determine the auditory acuity, the only exact way is to use the threshold methods referred to above; most of these methods are as yet too difficult or too circumstantial to permit of extensive application. In otiatry, therefore, various rough-and-ready tests, serving for general orientation as to hearing power, have been introduced. One tests the ear first for sounds of different kinds. Thus the power to hear spoken and especially whispered words is examined, preferably in a still, closed room. The average distance at which whispered, sounds can be heard (the whisper being produced with the aid of the residual air left in the thorax after deep expiration) is about 25 meters in a very quiet room, about 20 meters in ordinary rooms. A patient whose hearing permits these words to be heard as far away as 6 meters suffers no practical inconvenience. Each ear is tested separately, the patient standing at the end of the room, the other ear being tightly closed with the finger and the face and eyes looking straight forward so as to render lip reading impossible. Beginning at a distance of 6 meters a word is whispered, and the distance gradually decreased until the word is recognized and correctly repeated. If whispered words are not heard at all, one uses "conversational tones" in the same way. Spoken words can, however, be heard, when one ear is deaf, at a distance of 6 meters, even when the healthy ear is closed. To be sure about this, if the patient hears conversational tones at a distance of 3 meters when the good ear is closed and the bad ear open, one tries again when he closes also his bad ear (Lucae-Dennert test); if he can no longer repeat the test words, this proves that he heard with the bad ear, but if he still repeats them one can be sure that the bad ear did not hear. More accurate are measurements with Politzer's acumeter, an instrument which yields sounds of equal intensity; the drawback to it is that the noise it produces consists exclusively of a few high tones. For the same purpose the tick of a watch may be used. But the distance at which a sound can be heard is not a good measure of auditory acuity. The poorer the hearing in one ear, the more quickly a waning tone ceases to be perceived, and the measurement of the time a tone is heard is, therefore, an important aid in otiatric diagnosis. The numerical expression of defec- tive auditory acuity is not simple. If a patient, for example, hears the fork c for 92 seconds, while a normal ear hears it 183 seconds, the auditory acuity under test (H P) is not £ the normal acuity (H N) but a much smaller fraction, about -^ (Ostmann). This depends on the fact that during the waning of vibrations of a fork the intensity does not diminish by equal amounts in successive seconds; at first the intensity decreases rapidly, then ever more slowly. But for any measurement of auditory acuity which pretends to accuracy THE SENSES AND THEIR SYMPTOMATOLOGY 25 one must be able easily (1) to use tones of any desired pitch, (2) to use pure tones, (3) to measure their intensity exactly, and (4) to offer them to the ear in even intensity for any desired period. The instrumentarium which best meets these requirements is that of Wien, in which a telephone is used as a source for the tones, the sinusoidal alternating currents being yielded by a sinus inductor (for low tones) and by an alternating current siren (for higher tones). Having determined the degree of auditory defect, one has next to try to ascertain its cause; one must decide whether the defect is due to the sound- conducting apparatus (auditory meatus, tympanic membrance, middle ear) or to the sound-perceiving apparatus in the internal ear. The data to be gathered consist in the following: 1. Determination of upper and lower tone limits by means of the Bezold- Edelmann continuous tone series or more simply by tuning forks Cn c{ c4; the upper limit may be normal and the lower limit changed in middle-ear disease, while the opposite holds for labyrinthine deafness. 2. Rinne's Test (vide supra). — The difference between the time of air con- duction and of bone conduction should be noted in seconds for a fork having a pitch somewhere between c and c2. 3. Schwabach's Test. — Comparison of the time a fork is perceived when held on the vertex with the time in a person of normal hearing; the time is shortened in labyrinthine disease. 4. Weber's Test (vide supra). — The sound may be "lateralized" in one ear without artificial closure — toward the deaf ear in middle-ear disease, toward the healthy ear in labyrinthine deafness. 5. Gelle's Test. — If one compresses the air in one meatus by means of a rubber bulb, the tone of a fork held on the same half of the skull will be less loud at the moment of compression if the base of the stirrup be movable, while it will remain unchanged if it be fixed (ankylosis of the stirrup). Sight. — When the eyes are open the visual sensations are spatially extended and exteriorized as the so-called binocular visual field. If one eye is closed we project a monocular field. When both eyes are closed, or if they be open in the dark, there is a sense of blackness, something quite different from the absence of sensation corresponding to the region peripheral to the visual fields. There are two series of visual sensations: (1) An achromatic series — black, gray, white — which can be represented geometrically in their transitions by a straight line; and (2) a chromatic series — red, orange, yellow, green, blue, violet, purple (in all at least 160 tones at full saturation) — which can be represented geometrically in their transitions by a line which returns to the starting point, e. g., by a circle. This series of sensation is related to the achromatic series in such a way that the greatest saturation of each color occurs normally at a certain luminosity, e. g., yellow is brighter than orange when each is fully saturated. This relation of the chromatic to the achro- matic series gives rise to the so-called variables in sensations of color. There are three conditions of variability — the first dependent on quality, the second on luminosity, the third on saturation. The organ of visual sense includes the eye and a series of neurone chains in the central nervous system. The dioptric apparatus of the eye determines the mode of application of the adequate stimuli (light rays) to the sense organ proper, the retina. The impulses arise in the rods and cones and pass 26 DISEASES OF THE NKKVOUS SYSTEM through the bipolar cells and the ganglion cells of the retina into the optic nerve and thence to the primary and secondary optic centres of the brain. The whole path from the retina to the cortex, composed of several sets of superimposed centripetal neurones, is known as the visual conduction path. It is interesting that the different portions of the retina behave very dif- ferently in regard to color sensations; thus, at the fovea (central vision) and the area immediately adjacent (paracentral vision) the color sense is quite different from that of the more peripheral portions of the retina (e.rreiitric vision). Objects which seem colored in central vision may have different colors in paracentral vision, and may be colorless when excentrically viewed. In other words, the periphery of the retina is totally color blind and its vision is monochromatic; the central portion of the retina has polychromatic vision, while there is an intermediate zone which is partially color blind, having dichromatic vision. This explains why it is that the visual fields for colors are of different sizes even in the normal eye. The ether vibrations of the light rays lead to photochemical, histological, and electrical changes in the retina and give rise to the nervous impulses. The luminosity of a visual sensation is a function of the actual energy of the ether vibrations and of the parts of the retina stimulated. The eye cannot analyze white into its constituent components, and thus differs from the ear, which is able to recognize the partial tones in a clang. Color blindness is a deviation from the normal relations in a system of color sensations. It may be most properly defined simply as abnormal color sense. In its least abnormal form it manifests itself in a general weakening of the color sense, while in its most abnormal form no color can be seen at all but only differences in luminosity are distinguished. Between these extremes various deviations from the normal occur. The following may serve as a general classification of such abnormal cases.1 1. Abnormal polychromates, who see many colors but who differ from normal individuals (a) in that one or more color qualities are absent or (b) in outstanding color relations (e. g., in the similarity of certain colors to one another). These are the most common cases, and in the majority it is the colors red and green which are not distinguished. 2. Dichromates, who see only one pair of colors, these being complemen- tary, though sometimes different from the normal complementary colors. 3. Achromates, who see no colors at all, all lights giving sensations of gray in varying intensity. These are extremely rare. The theories of color vision deal altogether with the processes supposed to occur in the retina, neural paths, and centres. The theories are widely divergent, but may be roughly divided into three groups: (1) Which holds that there are three fundamental chemical substances in the retina reacting to the three so-called fundamental colors: red, green, and blue-violet; (2) which holds that there are three substances reaching respectively to red- green, yellow-blue, black-white, somewhat after the analogs' of anabolic and catabolic processes; and (3) which holds that there are no fundamental color processes, but that highly complex substances react variously for dif- ferent colors and for colorless light. As a matter of fact these theories are 1 A. Kirschmann, Normale nnd anormale ForbenKysteme, Arch. f. d. gesnmle Psijchol, 1907. THE SENSES AND THEIR SYMPTOMATOLOGY 27 pure constructions of the intellect; as yet no one of the postulated chemical substances is really known. Visual sensations depend not only upon the stimuli applied to the eye, but also upon the state of the eye at the time of application of the stimulus. The change in the eye in the different phases of activity is known as its power of adaptation. Among the phenomena which pertain to this function of adaptation are: (1) Positive and negative images; (2) light induction and color contrasts; and (3) the adaptations undergone by the eye in the light and in the dark. Studies of the dark-adapted eye make it probable that the rods of the retina are especially concerned with vision in dim light (night), while the cones of the retina have to do rather with vision in strong light (day). Localization of Visual Stimuli. — Two retinal stimuli which have the same value as regards quality and luminosity may differ in that they are pro- jected into different parts of the visual field. All the retinal excitations taken together give rise in consciousness to the continuous extended field. We concentrate our attention normally upon the point upon which our eyes focus, while the more peripheral portions of our visual fields are less focal in consciousness. The arrangement in space of visual perceptions, there- fore, depends upon the local sign which adheres to the sensation aroused by stimulation of each retinal point. The localization of visual sensations depends, however, not only upon this local sign, but especially in so far as measurement is concerned, also upon eye-muscle sensations. In examining a patient clinically regarding his capacity for visual sensa- tions we are provided with very exact methods and delicate apparatus. Here we can call attention only to some of the methods most essential for neurological diagnosis, especially to (1) the determination of visual acuity, (2) the determination of the type of central vision, (3) the determination of the capacity for vision in dim lights, (4) the determination of the extent of the visual fields, and (5) the ophthalmoscopic examination. In determining the visual acuity, one uses letters or similar signs, made so as to be as long as they are broad ; the strokes of the letters should be of even thickness and one-fifth of the thickness of the whole letter (e. g., Snellen's "Optotypi"). The visual acuity V (visus) is expressed by a fraction whose numerator gives the distance d in which the latter is recognized, and whose denominator gives the distance D which corresponds to a visual angle of five minutes for the letter: V=^. The dioptric apparatus must be borne in mind (anomalies of refraction, accommodation) and, if faulty, the visual acuity determined before and after correction. In determining the types of central vision we decide whether the patient has polychromatic (normal), dichromatic, or achromatic vision. For this Holmgren's colored wools are very satisfactory. From a large collection of wools of different color one chooses one of rose-color (pale bluish red) and asks the patient to put beside it from the collection all the wools of the same color, telling him that he may make mistakes either by choosing wools of a wrong color or leaving behind wools of the same color. If his vision be dichromatic, the patient will pick out bluish green and gray wools and put them with the rose-colored wools. If his vision be achromatic, he will be wholly unable to discriminate among the wools except by differences in brightness. One may use Adler's colored crayons or Stilling's pseudo- 28 DISEASES OF THE NERVOUS SYSTEM isoehromatic charts, Nagel's lantern with colored lights, or color equations with rotating discs. In determining the capacity for vision in dim lights, one darkens the room and finds out whether the patient sees as long as the examiner and whether his eye becomes dark-adapted as quickly. For quantitative tests, Foerster's photometry or Masson's disc may be employed. The determination of the extent of the visual field for each eye (perimetri/) is of very great importance in neurological diagnosis. A rough test may be made by seating the patient with his back near a window before the examiner; a bandage is placed over one eye and he is told to look with the other into the eye of the examiner opposite (distance, 40 cm.). Closing one eye, one holds the white or colored object (1 cm.) midway between the patient and the examiner and controls by the extent of his own visual field the examination of that of the patient. With a little practice one can detect existing hemi- anopsias, scotomata, or concentric contractions easily; the method is impor- tant for quick preliminary orientation. For exact registration of the extent of the visual fields, Foerster's perimeter or some similar apparatus (e. g., Sydow's) should be used; self-registering perimeters are obtainable, but are not necessary. Care must be taken to avoid fatigue; one should not work too long at one visual field, but determine limits quickly (though accurately), encouraging the patient frequently to give the matter his closest attention. The patient is told that while he may wink as often as he likes, he is to look straight forward at a fixed point and on no account to follow the object with his eye. The objects are brought in from the periphery and the patient announces the time of first appearance and the color; white objects are brought in vibrating, colored objects quietly, from the periphery. No one color field should be determined all at once, but one tries different colors, so that the patient never knows which color is entering the visual field. If a defect (scotoma) be found, its limits may be very accurately localized by using small test objects (2 mm. broad). For testing color fields, one usually uses green, red, and blue, the field for the former being smallest, that for the latter largest, under normal conditions. There are great individual differences, however, in normal color fields, and much depends upon the exact colors used. If a green which is comple- mentary for a red be employed, the fields for red and green are approxi- mately co-extensive. The technique of ophthalmoscopic examination should be learned and regularly practised by every active physician. Through it we are able to look directly at the papilla n. optici, a part of the central nervous system, and, from it, to draw conclusions regarding a whole series of nervous dis- eases; it is one of the chief aids to neurological diagnosis. The examina- tion in the inverted image is more desirable than in the upright image, since the technique is easier and a wider view of the retina is afforded; the upright image is, however, very valuable for the study of finer details. As to the papilla n. optici itself, one notes any changes (a) in the normally distinct boundaries, and (6) in its normally delicate rose color. It is to be borne in mind that the temporal half of the papilla is normally of a somewhat lighter rose color than the nasal, but it is never really white. The centre of the papilla often looks white normally, owing to the "physiological" excavatio papillae; the periphery is, however, always rose color. Acquaintance with DISTURBANCES OF SENSATIOX 29 the normal appearances of the arteriole.s and venules of the retina, the color of the eye-ground, and the macula lutea should be cultivated, in order that abnormalities may be recognized. DISTURBANCES OF SENSATION. General Remarks. — Having reviewed (1) the sensations mediated by the various sense organs and centripetal conduction paths, and (2) the methods of investigating them clinically, we may turn to a general consideration of the disturbances in disease. In certain diseases like tabes and multiple neuritis a whole series of sensory conduction paths may be simultaneously disturbed; in other pathological conditions (e. g., tumor, vascular lesion), one sense organ or one sensory conduction path may alone be affected. In intoxica- tions there may be elective injury with loss or perversion of particular sensory function (e. g., tobacco amblyopia, cinchonism). It is customary to divide sensory disturbances into subjective and objec- tive. By subjective disturbance one means those which are announced spontaneously, in the consciousness of the patient; by objective disturbances, those abnormalities of sensation recognized by the patient when he himself or his physician applies adequate stimuli to his organs of sens£. Subjective disturbances are nearly always pathological sensations which arise, owing to (1) abnormal internal stimuli (acting on the sense organ, conduction path, or cortex cerebri), or (2) abnormal increase in excitability of these parts. The pathological sensations may not differ in quality from the sensations producible by adequate stimuli; when they do differ (e. g., formication), they are spoken of as dyscesthesias or as parcesthesias.1 Objective disturbances are usually classed under the headings: (1) Ances- tkes-ia, (2) hypercestkesia, and (3) paraestliesia, corresponding to (1) decrease or loss, (2) increase, and (3) perversion of sensibility. This is a very crude classification, and must sooner or later be modified and extended. A more rational classification is needed, and we shall doubtless from now on begin to classify anomalies of sensation according to changes in (1) quality, (2) intensity, (3) reaction time, (4) duration, (5) feeling tone, (6) localization or e.rferiorization, (7) fusion, (8) adaptation, (9) fatigue, and (10) relation to rrfle.r, affective, and associative processes. By anesthesia is meant a condition in which an adequate stimulus no longer arouses a sensation. Anaesthesia may be temporary (e. g., hysteria, cocainization) or permanent (e. g., optic atrophy). It may be peripheral in its origin (sense organ, centripetal nerve) or central (conduction path, cor- tical sense area). Aside from the complete loss of sensation which anaes- thesia denotes, conditions of hypcestlwsia are met with in which the sensations aroused by adequate stimuli are less intense than normal, or the physical stimulus necessary to elicit a just perceptible sensation must be stronger than normal (elevation of intensity threshold). In hypercestfiesia stimuli when applied call forth sensations of greater intensity than normal or a stimulus normally subliminal possesses a 1 The term parccstliesia is used very loosely; some mean by it abnormal sensations like formication; others use it for anomalies in reaction time, fusion, localization, etc. 30 DISEASES OF THE \KRVOUS SYSTEM threshold value (depression of intensity thresliold). Much of what is designated hypersesthesia clinically is really an affective state due to abnormal negative feeling tone (e. g., the "acoustic hyperaesthesia" of psychoneurotics). The "positive or pleasurable feeling tone" of other sensations may be lost (anhe- donia), diminished (hyphedoma), or increased (hyperhedonia); changes here are met with especially in men till diseases. The area of sensory surface in which the anomaly of sensation exists, or so-called distribution or extent of the anaesthesia or hyperaesthesia, should be accurately determined and its limits exactly recorded, since these are of much importance in differential diagnosis, permitting one frequently to locate the lesion in periphery, spinal cord, or brain. When an organ of sense is diseased it is important also to make sure whether the anomaly concerns all the sense modalities or sense qualities mediated by it (total anomaly) or only certain of them (elective anomaly). Thus, as an example of an elective anomaly of cutaneous sense, the condition often met with in syringomyelia may be mentioned in which touch sense may be intact when the sense of temperature and pain is abolished. The apperception time for sensation may be pathologically delayed (e. g., delayed pain and touch sensations in hypaesthetic, or more often hyperaes- thetic, areas in neuritis and tabes). The localization and exteriorization of sensations are sometimes abnormal. Irritation of a nerve trunk is, according to the "law of excentric localization," always referred to the region whence the nerve receives normally its cen- tripetal impulses; thus, when one "hits his funny-bone," the little finger tingles, and in amputation neuromata the disagreeable sensations are referred to the lost member. Again, a stimulus applied to one part of a sensory surface may be localized in another; in tabes, hysteria, and multiple sclerosis a skin stimulus to one leg may be localized in the other (allocheiria or allcesthesia) . When a stimulus applied to one point is properly localized there but gives rise also to a subjective sensation (perhaps of wholly different modality) localized elsewhere we speak of syncesthesia.1 There may be anomalies of fusion of sensations; stimuli which should be felt as continuous and simultaneous may be experienced as successive, and one touch to the skin felt as two or more, or two compass-points as three or four (polyoesthesia) . This phenomenon, in the writer's opinion, is sometimes due to stimulation simultaneously of a number of touch points; owing to the pathologically delayed apperception time for some of them, the sensation of several separate, successive stimuli is experienced rather than normal unitary sensation, which depends upon fusion of simultaneous stimuli. Here an apparent faulty fusion would in reality be prolonged apperception time of some stimuli, due probably to delayed conduction. On the other hand, fusion of sensations may sometimes occur when normally they would be felt separately (change in "successive threshold"); this is seen in the pain sense of the skin occasionally when a number of pricks applied succes- sively, though not felt at all at first, give rise a little later to a continuous sensation. This is closely allied to the so-called summation of excitations. Disturbances in Individual Sense Domains. — Anomalies of Pain Sense. — Subjective anomalies are very common. Spontaneous pains occur in 1 Smith, H. L., Johns Hopkins Hospital Bulletin 1905, xvi, 256. Here belong the so-called sound feeling, color hearing, or sound seeing, and number form. DISTURBANCES OF SENS AT I OX 31 various organic diseases (e. g., neuritis, tabes, visceral diseases), as well as in so-called functional diseases (psychoneuroses). Neuralgias, cephalalgias, hemicranias, visceralgias, and topoalgias or psychalgias are symptoms met with daily. In studying abnormal pain sensations, the elements of the pain should be carefully analyzed, its relations to space and to time, the exact quality of the pain, its topography, and any accompanying phenomena should be attended to. The modifying influence of position, of motion, of pressure, of food, of drugs and chemicals, and of the organic functions of the body should be looked into. The excellent treatise of Schmidt1 can be heartily recommended as a valuable guide to the interpretation of pains complained of by patients. Anaesthesia in the domain of the sense of pain is called analgesia, while hyperaesthesia here is called hyper algesia. When spontaneous pains appear in an anaesthetic area, we speak of analgesia dolorosa. Anomalies of the Deep or Mesoblastic Sensibility. — Anaesthesia in this domain has been designated bathyanaestJiesia (Oppenheim). (1) Anomaliesof tlie sense of position. Hypaesthesia and anaesthesia are common in neuritis and tabes. If a limb be placed in a certain position, this can be only imperfectly or not at all reproduced by the opposite limb. (2) Anomalies of ttie sense of movement. If anaesthesia exists, passive movements are not felt; if hypaes- thesia, greater excursions than normal have to be made to arouse the sen- sation of movement (elevation of threshold). Not only the extent, but the direction of the movement may be mistaken in these kinanoesthesias. As a result, there is disturbance of the coordination of movements, or ataxia. Localized loss is often cortical in origin and helps in topical diagnosis (cere- bral tumor, etc.). (3) Anomalies of the sense of resistance and weight. This sense is prone to suffer also when the sense of movement is disturbed. Weights are improperly judged and the difference sensibility is altered. (4) Anomalies of stereognostic perception. In disease the stereognostic perception may be more or less impaired, even to complete loss (astereognosis of C. K. Mills). It may be lost even when the sense of touch, temperature, and pain are normal. Astereognosis is common in hemianaesthesia of cerebral origin, but it is difficult to be sure about it unless the accompanying hemiplegia is so slight as to permit the patient to make the movements necessary in palpation. It is more likely to be present if the hemianaesthesia be cortical (Regio centro- parietalis) in origin rather than capsular, pontine, or bulbar. In the cerebral palsies of children the power of stereognostic perception may never develop. Astereognosis will appear in tabes and peripheral neuritis if the sensory con- duction paths from the upper extremities be involved. Astereogenosis is sometimes a symptom in hysteria. (5) Anomalies of the vibration sense (osseous sensibility}. Anaesthesia of the bones to the vibrating tuning-fork (pallanoesthesia} is common in neuritis, tabes, syringomyelia, haematomyelia , Brown-Sequard paralysis, myelitis, cerebral hemianaesthesias, and hysteria (Dejerine). Anomalies of the Vest ibular and Allied Senses. — Vertiginous Disorientation. — Disturbances of the vestibular or labyrinthine sense in its two components: (a) Sensibility to acceleration in a straight line (sense of the vertical direction and of progressive, non-rotary movements), and (b) sensibility to angular 1 Pain: Its Causation and Diagnostic Significance in Internal Disease. English translation by Vogel and Zinsser, 1908. 32 DISEASES OF THE NERVOUS SYSTEM ;irrrl<>rations (sense of change of velocity of rotary movements) — have only recently had attention more carefully directed to them. A remarkable phenomenon associated with disturbance (even temporary) of the vestibular sense is an illusion regarding the state of movement of the body, a deception as to its momentary stability, in which one has the mis- taken sensation either (1) that objects in the environment are revolving around one's body, or (2) that the body is rotating around one of its axes. This sensation, often accompanied by a decided feeling of discomfort, occa- sionally, even with nausea or vomiting, constitutes the form of dizziness or vertigo known as sham-movement vertigo (to distinguish it from height vertigo, felt on looking downward from a great height or upward on a steep wall). This sham-movement vertigo appears to be the result of a "contradiction' of one set of sensations by another. If one of our sense organs signals "the body is at rest," and another signals "the body is in motion," or if the signals conflict regarding movement in the environment, we feel confused, disoriented, dizzy. This vertiginous disorientation is most often due to a dis- crepancy between the reports given us by our vestibular sense and those emanating from other sense organs; it is usually associated with a tendency to move the body in a direction opposite to a movement really occurring or to a sham movement, and, indeed, the body is often so moved. This feeling of vertigo can be aroused by stimulating the N. vestibuli in various ways: (1) By rotating the body around any one of its axes; (2) by moving the body progressively in a curved path (swinging; pitching of a ship) ; (3) by passing a galvanic current through the head from one ear to the other (galvanic vertigo). Here the abnormal vestibular sensations con- tradict visual, muscle-joint, and tactile sensibility. But the same sensation can be aroused when vestibular sense is normal through contradictory abnormal sensations of sight or of eye-muscle movement, e. g., whenever binocular vision is suddenly disturbed (eye-muscle paralysis), or whenever the image in one eye is sharply focussed and the other is blurred. Further, in cerebral lesions (local irritation of abscess), cerebral anaemia or cerebral in- toxications (acute alcoholism), in all probability, the central stimuli affect sensory neurones of certain modalities more than others, so as to produce contradictory impressions with resulting disorientation. Obviously, then, any factors which disturb the functions of the vestibular nerve or its central connections or the eye-muscle apparatus (peripherally or centrally) may cause vertigo, especially if the disturbance take place quickly. Many deaf mutes experience no vertigo on rotation, probably owing to loss of function of the labyrinth. Anomalies of Other Interior Sensations. — Hunger. — Hypaesthesia and anaes- thesia in this domain are met with in the various grades of anorexia; hyper- aesthesia, expressed as exceedingly strong feeling of hunger, is called bulimw, or "wolf hunger;" when this is accompanied by powerfully unpleasant feeling tone, the patient describing it as painful, it is called gastralgokenosis (Boas). The sense of satiety may be diminished or abolished (akoria, aplesia); patients (tumor cerebri, dementia) may then ingest extraordinary amounts of food and yet remain entirely unsatisfied; they exhibit polyphagia. The feeling of nausea is probably an affective state rather than a sensory disturb- ance in the strict sense. Gastralgia (including cardialgia and pyrosis) is a disturbance of visceral pain sense. DISTURBANCES OF SENSATIOX 33 Thirst. — Abnormal thirst occurs in diabetes and often also in the psycho- neuroses; it may lead to excessive drinking (polydipsia] , and is probably central in origin. Fatigue. — Under abnormal feelings of fatigue are often grouped three distinct varieties of sensations: (1) The painful weariness or feeling of being completely "knocked out" which is associated even with slight exercise in many nervous patients; (2) the weakness which is experienced by patients who have paralysis or paresis of muscles; and (3) the general lassitude felt on slight exercise in states of exhaustion, in which slight movements cause palpitation, dyspnoea, perspiration, tremor, and faintness. Sexual Sense. — Anaesthesia of the sexual sense (abnormal frigidity} may be present owing either to loss of libido or to dyspareunia; the libido may be pathologically increased, as in nymphomania and satyriasis; for various per- versions of tlie libidos, pecial texts may be consulted. The hypersesthesia of the vagina (with painful contraction of the constrictor cunni), known as vaginismus, is an anomaly of visceral pain sense and nearly always associated with abnormal affective states. Anomalies of the Sense of Touch or Pressure. — It is only recently that clini- cians have begun to separate sharply anomalies of this sense from anomalies of pain sense, owing to the mistaken idea that pain is due to overstimulation of the same nerves which on milder stimulation respond by contact or pressure sensations. Anaesthesia and hypsesthesia of the touch sense very frequently occur; it is doubtful whether true hypersesthesia of this sense has been observed. The distribution of the anaesthesia or hypaesthesia is impor- tant for topical diagnosis, as is also association with (or dissociation from) anomalies of pain and temperature sense. Spontaneous itching (pruritus) is regarded as a dyssesthesia (or paraesthe- sia) of the touch sense by some, as are also the "creepy sensations" known as formication. Pruritus appears to be due to pathological stimuli affecting the nerve endings in the skin (intoxications), formication rather to pathological stimulation of nerve trunks in their course, the sensations being referred to the periphery (law of excentric localization). Special forms of formication are met with in acroparcesthesia (tingling and pain at ends of extremities), in meralgia paraesthetica (dysaesthesia in domain of N. femoris lateralis), and in erythromelalgia (painful redness of legs). In these various conditions the touch sense is rarely involved alone, pain sense and the temperature senses may also be involved, and the writer considers that the peculiar qualities of sensations known as dysaesthesias (or paraesthesias) are due to the unusual combinations of sense modalities which result from pathological stimuli. Anomalies of the Temperature Senses. — Subjective feelings of chilliness or cold or heat are common in infections (e. g., initial chill), and in the psychoneuroses ("hot flushes"). The feeling of heat (especially in the back) which occurs in paralysis agitans is well known, and patients suffering from exophthalmic goitre frequently complain of abnormal sensations of heat. In cutis anserina the "chilliness" contains besides its cold component also a factor due to the stimulation of the touch points by contraction of the musculi pilorum. In objective disturbances the ther- maneesthesias usually involve cold sense and warmth sense simultaneously, but this is not necessarily tjie case; there may be loss of cold sense (kryanaes- thesia or alganaesthesia) without change in warmth sense, or there may be loss of warmth sense (ardancesthesia) without involvement of cold sense, VOL. vii. — 3 34 DISEASES OF THE NERVOUS SYSTEM the latter dissociation being more frequent than the former. Thermhypces- thesias are common ; thermhyperoesthesia is rare, much that is described as such being in reality hyperalgesia. Topographical Distribution of Disturbances of Sensation. — Disturbances of cutaneous and deep sensibility, especially studied accurately as to their topographical distribution on the surface of the body, throw much light upon the site of the lesions which give rise to them. In the peripheral nerve trunks and in the roots of the spinal and cerebral nerves the fibers which carry centripetal impulses are more intimately mixed with one another than are their intracentral communications, and this explains why it is that dissociations, although they occur in peripheral and radicular lesions, are more common when the pathological process is located in the spinal cord or cerebrum. Anomalies of the Sense of Taste. — Anaesthesia in this domain is known as ageusia, hypaesthesia as hypogeusia, and hypersesthesia as hypergeusia. If one or more of the four fundamental qualities of taste sensations remain intact when others are abolished, we speak of an elective ageusia. Aside from lesions of the peripheral neurones and certain gustatory hallucinations, the pathology of the sense of taste is as yet a terra incognita. Various perversions of the sense of taste have been described under the designation parageusia. Anomalies of the Sense of Smell. — Here, similarly, we have to deal with anosmia, hyposmia, and hyperosmia, which may be total or elective. When an anosmia is due to interference with the passage of odoriferous air currents toward the regio olfactoria it is called an anosmia respiratoria, a subdivision of which is the anosmia gustatoria when the odoriferous currents from food and drink by way of the choanae are obstructed. Anosmia may be due also to disease of the regio olfactoria itself (tobacco poisoning; syphilis) or to intracranial lesion of the olfactory nerves, bulbs, tracts, or centres. The left- sided anosmia which sometimes accompanies right-sided hemiplegia and aphasia is said to be due to lesion of the lateral root of the olfactory tract. In hysteria a unilateral "functional" anosmia frequently accompanies, or rather forms a part of, the hysterical hemiansesthesia. Anosmia may be a congenital anomaly, and hyposmia is common in imbeciles, although not constant, some imbeciles appearing to be hyperosmic. Anomalies of the Sense of Hearing. — Total deafness is known as anacn#is, partial as hypacusis, while abnormally sharp auditory acuity, rarely met with, is hyperacusis or true hyper&sthesia acustica.1 The painful sensations in the ear felt when noises or tones are heard not only in diseases of the middle and internal ear, in otitic paralysis of the N. facialis, in trigeminal neuralgia, in migraine, and in many psychoneurotic states has been called dysacusis (false hypercesthesia acustica); in facial paralysis it takes especially the form of increased sensitiveness to noises, and has been called oxyako-ia. The so-called paracusis Willisii, met with especially in sclerosis of the middle ear, is of but little importance neurologically ; the name is used when a deaf person subjected to an acoustic stimulus ordinarily infraliminal for him hears the sound when other sound stimuli (noises) are acting simultaneously ; thus, many deaf people hear better when travelling in a train than when at home. The term paracusis has also been used to mean the hearing of a tone 1 The latter form has unfortunately been applied to the pain, or negative feeling* - tone experienced by psychoneurotics when noises or even sounds of any kind are heard. DISTURBANCES OF SENSATION 35 as although higher or lower in pitch than it really is; when one ear hears the tone of normal pitch and the other higher or lower, we speak of diplacusis. But little is known as yet regarding auditory disturbances due to lesions of the central auditory paths; the latter, owing to the semidecussations at the corpus trapezoideum, are laid down bilaterally, the lemniscus lateralis, etc., on each side containing conduction paths from both ears. Focal lesions in the pons and midbrain (involving the lemniscus lateralis or the colliculus inferior) or higher up (involving the medial geniculate bodies or the auditory radiations) cause disturbances of hearing on both sides (not complete deaf- ness on either side). Total unilateral deafness is sometimes caused by neurofibroma of the N. acusticus, but usually only after the tumor has attained to a considerable size; the deafness is here due chiefly to the lesion of the peripheral (not the central) auditory neurones, although it may be due in part to involvement of the nuclei terminales N. cochlearis (dorsal and ven- tral). Cortical lesions involving the auditory sense areas in both temporal lobes must be widespread to cause total "cortical deafness," a clinical fact in accord with the experiments of Munk. Anomalies of the Sense of Sight. — Anaesthesia in this domain is known as anopsia, hypaesthesia as hypopsia, and hyperaesthesia as hyperopsia. Anopsia (amaurosis or blindness} or hypopsia (amblyopia) may involve the whole of one eye or of both eyes. Or one-half of each retina or its conduction paths may be blind, leading to loss of half of the visual fields (hemianopsia)', if it be the two right halves or the two left halves of the visual field which are lost, we speak of hemianopsia homonyma (due to lesions of visual sense area in the cortex, of occipitothalamic radiation, or of one tractus opticus), while if it be the two medial (nasal) halves or the two lateral (temporal) halves (the latter due to chiasm lesion) of the field, we call it hemianopsia heteronyma. If a hemianopsia involve the color sense only or chiefly, it is called a hemi- chromatopsia; if vision be present in half the field but dimmed, the condition is designated hemiamblyopia. A hemianopsia is said to be total when the line separating the blind area from the area in which the field is still visible passes perpendicularly through the fixation point; if the visual field is not so limited, but encroaches upon the blind area, the hemianopsia is not total and the area of encroachment is called the surplus field (Wilbrand). Sometimes this surplus field is so large as to occupy a whole quadrant of the visual field and then a quadrantic hemianopsia is spoken of. There are even references in the bibliography to sextantic and octantic hemianopsias ; when the loss in the visual field is as small as this, however, it is probably better to call it a scotoma, as this name is applied to small areas of loss or defect in the visual field, such as the blind spot, which exists normally. It is customary, however, to reserve the term scotoma for a defect in the visual field which does not reach the periphery. A central scotoma is one situated at or near the fixation point; if it involve only sensations of red and green, it is called a relative scotoma (e. g., in chronic form of retrobulbar neuritis, limited to the papillo- macular bundle, most often seen in alcoholism or tobacco poisoning), while if no light be sensed in the defect it is said to be an absolute scotoma (met with in diabetes, multiple sclerosis, and occasionally "idiopathically"). When the visual field is restricted regularly at the periphery we speak of concentric restriction or contraction of the msiial fields; when this is due to progressive diseases of the Nn. optici (primary and secondary optic atrophy) the contraction proceeds from the periphery centralward, the central acuity 36 DISEASES OF THE NERVOUS SYSTEM for white and colors (especially green and red) also suffering early; the vision is "fogged;" then marked disturbances of orientation supervene. The beginning and progress may be very insidious in simple (so-called primary) progressive atrophy (tabes; dementia paralytica), while the fogginess and darkness may come suddenly in neuritis (meningitis; lues). In choked disk (tumor, lues, brain abscess, hydrocephalus) vision may remain good for some time; if the cause persists, there will be gradual loss, due to atrophy; the color sense may go first, and, finally, there may be complete loss of the visual field. Bordley has made a careful study of the color sense in cases of increased intracranial tension, especially when the latter was due to tumor. It is interesting that the contraction of a visual field due to glaucoma is especially marked in the medial field, the last of the field to go being an excentric temporal area (glaucomatous visual-field slit) ; in contrast to what happens in simple optic nerve atrophy the color sense remains long intact in the retained field and the central visual acuity is longer maintained (Axenfeld). In detached retina there is contraction of the field corresponding to the degree of detachment; this may in daylight affect, at first, colors only, especially blue, although in dim light the contraction is absolute. Recent retinitis due to nephritis or diabetes frequently injures central vision and may give rise to central scotomata of different kinds corresponding to the various patches and hemorrhages; the periphery is less often injured. In retinitis pigmentosa and in the retinal atrophy following syphilitic chorioretinitis there may be either marked concentric contraction of the visual field, or, in cases in which the degeneration attacks an intermediary zone of the retina, a so-called ring scotoma which later extends both peripheralward and centralward. Central vision may, despite this, be long retained as an "island" of good visual acuity and good color vision, the patient seeing as though through a tube of small caliber. Similar limitations of the visual field are met with in hysteria and in traumatic neurosis; here, however, by testing first at a distance of 10 cm. (and marking limits with chalk) and then at a distance of a meter, the visual field does not correspond- ingly enlarge, the psychoneurotic state here behaving like that of a simulant. In contrast with the immobile positive scotomata (due to diseases of the retina or visual path) above described, the mobile positive scotomata (movable shadows) due to turbidity of the corpus vitreus should be borne in mind. In neurasthenics and myopics these musca volitantes may be present when the vitreus is normal (myodesopsia) ; the threads, flocculi, veils, chains, etc., seen in certain cases may, however, be due to pathologically formed elements in the vitreus visible with the ophthalmoscope. Important for neurologists, too, is the so-called fortification scotoma of migraine; a positive and sharply localized sensation of glimmering followed by darkening due to irritation of the retina or visual sense area. Sudden blindness of one eye may be due to embolism or thrombosis of the arteria centralis retinae. Other sudden disturbances of vision may occur in (1) cerebral hemorrhage involving the central visual paths (hemianopsia associated with other symptoms of cerebral apoplexy); (2) retinal detach- ment (disturbance beginning at periphery of visual field, preceded by char- acteristic irritative phenomena); (3) choked disk (obscurations temporary). Less sudden but rapid blindness may occur in (1) very acute inflammatory glaucoma (excruciating unilateral headache) ; (2) large hemorrhages into the DISTURBANCES OF SENSATION 37 corpus vitreus (red or green stripes before the eye precede the blindness); and (3) acute retrobulbar neuritis. The terms nyctalopia and hemeralopia need explanation. When a patient can see better in dim light (or when the eye is in shadow) than in bright light he has nyctalopia (e. g., in beginning cataract, the widening of the pupil in dim light leaving more transparent lens uncovered). When, on the other hand, a patient does not see at all in dim light, or only after long adaptation, hemeralopia or night blindness exists (retinitis pigmentosa; chorioditis diffusa; glaucoma; retinal detachment; general disturbances of nutrition). By photopffia is meant an abnormal sensation of color or light due to retinal lesions, or to central irritation, by metamorphopsia, the distorted vis-ion, occurring in lesions of the retina and chorioid, in which straight lines look curved or jagged, or letters seem out of place. The term macropsia is used to designate the symptoms "of seeing things too large" (e. g., strained accom- modation), while micropsia is the term for "seeing things too small" (e. g., paresis of accommodation) ; both macropsia and micropsia may be met with in the psychoneuroses. In many functional nervous cases a study of anomalies of refraction has an important bearing upon etiology and treatment. We distinguish the nor- mally refracting eye (emmetropia) from the short-sighted eye (myopia) and the far-sighted eye (hyperopia, hypermetropia). When in order to secure normal visual acuity it is necessary to use not simple spherical lenses, but lenses which correct certain meridians only, the condition of astigmatism exists; if the curvature in each meridian is equal throughout its course, but the curva- tures of different meridians vary so that the meridians of greatest and least curvature are approximately at right angles to each other the astigmatism is regular; when the vertical meridian has the greatest curvature it is astig- matism with the rule, but when the horizontal meridian has the greater it is astigmatism against the rule. The astigmatism is irregular either when the meridians of greatest or least curvature are not approximately at right angles or when the curvature in a single meridian is irregular. Anomalies of vision due to disturbances of accommodation and convergence may also be mentioned here, although they belong more properly to disturb- ances of motility. If near vision is faulty, or cannot be maintained long, asthenopia exists. If this is due to faulty power of accommodation, it is known as accommodative asthenopia. The most frequent form of this is due to the progressive sclerosis of the crystalline lens, which normally •diminishes the power of accommodation as life advances, and soon after the fortieth year the near-point of a normal (emmetropic) eye comes to lie more than 25 cm. distant (presbyopia). Accommodative asthenopia due to paralysis of the M. riliaris often follows diphtheria. Another form of defective near vision is muscular asthenopia, especially that due to faulty convergence (most often seen in incorrected myopia) with consequent faulty binocular near vision (convergence asthenopia). The lesions of the eye, most important for the neurologist, discoverable by the ophthalmoscope, may be briefly referred to here. In optic neuritis the papilla looks turbid, grayish red in color, its margins are indistinct, and there are often minute hemorrhages in or near it and the veins may be tortuous and dilated. It is most often due to cerebral disease, especially when bilateral. If the papilla be swollen (2 diopters or more) and enlarged, we speak of choked disk; it is most often due to increase of intracranial pressure (bnun 38 DISEASES OF THE NERVOUS abscess, hydrocephalus, syphilis, tumor).1 Unilateral optic neuritis occurs in diseases of the orbit, in various infections and intoxications, and in begin- ning tumor, etc. Optic neuritis may be followed by optic atrophy; the papilla has indistinct margins, but becomes whiter as the swelling goes down; the arteries gradually narrow and have white sheaths (neuritic optic atrophy). Retrobulbar neuritis occurs in two forms — acute and chronic. The acute form is seen in rheumatism and in multiple sclerosis, the chronic in diabetes, in various intoxications (tobacco, alcohol), and sometimes when its cause is not known. Here the ophthalmoscopic picture is very different from that described above for "optic neuritis;" no distinct alteration can be seen in the papilla N. optici for some time, although after a while a retrograde atrophy leads to pallor, especially on the temporal side of the disk. When the papilla N. optici looks white, grayish white, or greenish white instead of its normal rose color there is atrophy of the optic nerve (atrophia N, optici); ophthalmologists distinguish several types: (a) Simple atrophy, (6) retinal atrophy, (c) glaucomatous atrophy, and (d) neuritic atrophy. Of simple optic atrophy in which there is simply pallor of the disk with retention of its well-outlined margins and but little change in the vessels, three main types are described: (1) That occurring in tabes and dementia paralytica, the changes in the disk being visible from the beginning of the visual disturbance; (2) retrograde atrophy, following upon diseases at base of brain, e. g., tumors, chiasm lesions, sphenoidal-sinus disease, etc., the changes in the papilla becoming visible through the ophthalmoscope only after the visual disturbance has lasted some time; and (3) atrophy after occlusion of the A. centralis retince, in which the simple atrophy differs from (1) and (2) by the existence of a high grade of vascular constriction. The so-called retinal atrophy of the optic nerve is characterized by a yellowish-white turbid papilla, constricted bloodvessels, and degeneration of the peripheral retina; it occurs in diffuse degenerations of the retina (chorioido-retinitis ; retinitis pigmentosa). The form of atrophy accompanying chronic glaucoma is very characteristic. The increased intra-ocular pressure leads to "glaucomatous excavation," and this after a time is followed by atrophy with abrupt kinking of the blood- vessels at the margin of the papilla. Of the diseases of the retina revealed by the ophthalmoscope, the more important for the neurologist are: (1) Acute retinitis; (2) atrophy of the retina; (3) detachment of the retina; and (4) subretinal cysticercus. Of the diseases of the chorioidea discoverable by the ophthalmoscope, those which interest the neurologist especially are: (1) Chorioiditis disseminata, and (2) miliary tuberculosis; in both one sees gray or yellowish-gray rounded spots with ill-defined margins; some of them may be crossed by retinal bloodvessels. Anomalies of Sense Perception Known as Illusions, Hallucinations, and Pseudo-hallucinations. — Normal sense perception is more complex than mere sense impression; it involves association and assimilation. An "object" is composed only in small part of sense impressions directly received by way of the peripheral sense organ, but very largely of revivals of impres- sions earlier experienced (reproduced images; representations). A percept arises largely through the arousal of a host of old experiences by a few newly 1 See dishing and Bordley, Johns Hopkins Hospital Bulletin, 1909, xx, 95. DISTURBANCES OF PERCEPTION 39 entering sensations; perception is not, as it may seem, the mere entrance of a group of new sensations. The percept as thus constituted depends, espe- cially in its meaning or the value which it has in consciousness, upon the general direction of thought or upon the most outstanding idea in the imme- diately preceding moment; this is often, though inadequately, expressed by the term attention. We can profitably pass on to the consideration of the anomalies of sense perception known as sense deceptions, including illusions, hallucinations, and pseudo-hallucinations. In all these sense deceptions there is an "abnormal relation between the objective and the subjective setting, and the factors that control the course of the associations are not suited to the circumstances of the physical world." Events occur in accord with the laws governing normal perception, but the conditions are unusual and individual, not those which obtain with the mass of healthy people. By an illusion we mean a sense perception in which the subjective factor takes too large a part in the process of assimilation, so that the mental sup- plementation of the sense impressions entering into it leads to a result con- tradictory to the reality as determined in more accurate examination with the same sense organ or on correction by control through other senses. By an hallucination we mean a sense perception in which the abnormal relation between subjective and objective conditions is very pronounced; objective sense impressions may be entirely absent or present in unusually small amount and dissimilar to the content of the hallucination, and yet the sense perception is vivid, possessing for the patient the ear-marks of objective reality, being definitely localized in perceived space; the annihilation of the perception normally localized in this space is unexplained. By a pseudo-hall urination we mean a psychic experience which resembles a sense perception in intensity and in its involuntary appearance (thus, dif- ferent from a mere image, idea, or representation called up by association), but differing from a normal sense perception, from an illusion, and from an hallucination in that the patient notices the absence of the character of objectivity. We have then a series of transitionally related psychic phenomena begin- ning with sense impressions at one end and pure reproductions at the other, the series consisting of (1) sense impressions, (2) normal sense perceptions, (3) illusions, (4) hallucinations, (5) pseudo-hallucinations, and (6) pure reproductions (ideas, images, representations). In normal people in ordi- nary circumstances, the sense deceptions (illusions, hallucinations, and pseudo-hallucinations) do not occur; they are experienced occasionally by normal people in extraordinary circumstances and frequently in mentally abnormal people in ordinary circumstances.1 Illusions. — The psychic experiences known as illusions are best studied in connection with the sense of sight and hearing, since with these senses one can be sure as to the character of the external stimuli acting. Sounds heard and sights seen are misinterpreted owing to the incorrect supplementation (by 1 Some of the more important contributions to the general bibliography of sense deceptions are the following: Kahlbaum, Die Sinnesdelirien Allg. Ztschr. f. Psi/ckiat., xxiii, 1-86; Parish, E., Hallucinations and Illusions, 1897; Sully, J., Illusions, 1883: Text-books on Psychiatry by Krafft-Ebing, Kraepelin, and Paton have good chapters on the subject. The discussion in Storring's volume >t excellent. 40 DISEASES OF THE NERVOUS SYSTEM reproductions — images; ideas) of the sense impressions received. A melan- cholic patient, hearing the whistle of a locomotive engine, says that she hears the cry of her child being murdered, or, seeing a relative, fails to identify him as such, but takes him to be a stranger and impostor. Even normal people are often the subjects of illusion when the sense impressions are feeble and the mind is in a state of expectation; for example, an anxious mother may take the mewing of a cat for the cry of her sick child in a distant room. But the stronger and more distinct the sense impressions when illusions occur, other things being equal, the greater the degree of abnormality indicated. Defi- cient attention to sense impressions (as in alcoholic delirium) and short dura- tion of the sense impressions favor the origin of illusions. Tense expectation, emotional states or moods, a lively imagination, or pathologically increased facility of reproducing ideas will also favor illusion, for in these circumstances certain ideas are prone to he held focal in consciousness and they will obvi- ously have the best opportunity for cooperating with any sense impression which may enter. Where some idea is prominently in mind and the sense impression, simultaneous with it, gives rise to a sense deception, we speak of the idea or image as primary and the sense impression as secondary, the illusion resulting from the combination being an active illusion (Sully) or an apperception illusion (Kraepelin) ; where the entering sense impression finds no special idea focal in consciousness (the expectation or emotion existing having no definite reference), but by association arouses some image which, owing to the general state of consciousness at the moment, is particularly easy to reproduce, the sense deception resulting is said to be a passive illusion (Sully) or a perception illusion (Kraepelin). In insanity, illusions are probably just as important as hallucinations, the sense deceptions being due to the delusional ideas which are in consciousness at the time of entrance of the sense impressions. Hallucinations. — These may be elementary or complex. An elementary hallucination is one in which the subjective experience approaches that of a simple sense impression (e. g., a flash of light, a simple sound), while a complex hallucination is one in which the subjective experience approaches that of a compound sense perception (e. g., vision, voice). When the halluci- nations in the domain of a single sense are uniform in character, recurring monotonously in the patient's experience, they are called stabile hallucina- tions (Kraepelin's "perception phantasms"), experienced by many neuro- pathic individuals just before going to sleep, in which they see a certain flower, an animal, or a face, or hear a word pronounced always in the same manner; when the hallucinations vary greatly in their content they are spoken of as labile. If one sense only is involved at a time it is a unisensual hallucination; if two or more senses are involved simultaneously, as when the hallucinant sees the figures of the people whose voices he hears, the halluci- nation is disensual or multisensual. Hallucinations and illusions conform to the law of excentric projection or exteriorization of sense perception; the patient "projects" what he sees, hears, or feels into the external visual, auditory, or tactile fields, or localizes the sensation either in space outside or in various parts of his body. When a hallucination occurs in one sense domain as a result of actual peripheral stimulation of another sense domain it has been called a reflex hallucination (Kahlbaum). Hallucinations seem even more real to those who experience them than do normal sense perceptions; their power is irresistible; the patient is DISTURBANCES OF PERCEPTION 41 compelled to believe in them, the judgment being quickly overcome by them. This peculiar feature is due in part to the sensory distinctness, the seeming objective reality of the experience, but much more to the fact that hallucina- tions most often correspond to the pathological ideas of the patient, to his abnormal thoughts, fears, or wishes. Thus, although sense deceptions often play a part in the origin of delusions, some persistent direction of thought (Aufgabe) is still more often provocative of sense deceptions. Further, the strong feelings and emotions co-existent with the hallucinations go far toward giving the latter their power in the mental life. Among visual hallucinations the elementary types are represented by flashes of light or color, stars, flames, and the like, the complex tvpes bv visions in which, especially at night, illuminated animal and human forms appear, or God, angels, the Devil, or various horrible shapes may be seen ; if the hallucination occur in the daytime, which is less common, the patients complain of seeing a black dog, the face of a corpse looking in at the window, and the like. Sometimes in hemianopsia the visions are projected to the blind halves of the visual fields; occasionally, as in convalescence from alcohol delirium, visions which have begun to disappear may be recalled by pressure on the closed eyes (Liepmann). Even more influential in mental life than visual are auditor;/ hallucina- tions, the elementary forms of which are called akoasmata, the complex forms being known as phonisms or voices. The akoasmata consist of indefi- nite noises of different sorts — rustling, murmuring, thundering, bell-ringing, and the like; the phonisms or voices are often whispered words, more rarely words or brief sentences spoken aloud. The voices make unpleasant refer- ences to the patient, they insult him, abuse him, or threaten him ("rascal," "thief"). They may emanate from the patient's children, who are being murdered by an enemy, from a revengeful lover, from an annoying neighbor, or it may be the Deity or Satan who addresses him. Occasionally a voice may bring happiness and inspiration, but this is unusual; nearly always the voices irritate and pain, arouse suspicion and defence, cause anxiety or con- fusion; they may command, and the patient may be led to the most unnatural acts in the belief that he is obeying the order of a supernatural power. The patients can tell the distance and direction from which the voices come—- they localize them in space — a fact closely related to the objectivity (per- ception value) which attaches to the voices. If the voices are heard in one ear only, there is usually abnormal stimulation of the auditory path on that side, and the hallucination (or illusion) can often be called forth by electric stimulation. A word must be said about audible thinking (Gedankenlautwerden of the Germans), not of the delusional form of it in which the patient is convinced that his thoughts are audible to other people, although he does not hear them himself, but of the hallucinatory form in which a man hears his own thoughts, perhaps in his feet or in the ticking of a clock or the ringing of the doorbell. The patient hears the voices only when he pays attention to them. Sometimes a patient's thoughts seem doubly existent to him, first, in the normal way and then also as audible voices (double thinking} ; sometimes the voice dictates what the patient writes or it may repeat what the patient reads; occasionally the voice precedes the reading. Many of these "inner voices" are examples of pseudo-hallucination rather than of true hallucination. 42 DISEASES OF THE NERVOUS SYSTEM It is extremely difficult to distinguish olfactory and gustatory hallucinations from illusions of these senses, and the same is true of hallucinations of visceral sense. They are, however, of great practical importance, for they often account for the refusal of food. If the food smells of faeces or foul sweat, one can scarcely blame a patient for not eating it. In the domain of the cutaneous senses, tactile or haptic hallucinations and thermal hallucinations are not infrequently met with, the former especially in toxic psychoses; some of the subjective dyssesthesias may be hallucinatory in nature, as may also certain so-called psychalgia* or topoalgias (hallucinationft of pain sense). Much study has been devoted also to hallucinations of the movement and position senses, sometimes referred to as kincesthetic hallucinations. They lead to the maintenance of peculiar attitudes and also affect the voluntary movements, being sometimes the cause of imperative positions or monotonous defensive movements. The hallucinations may concern the eye-muscle movements, the locomotory movements, or the speech-muscle movements. Sometimes there are hallucinations of vestibular sense, the patient having the sensation of progressive or rotary movement. Doubtless many impulsive acts and various psychomotor inhibitions are traceable to hallucinations as a cause; in epilepsy and alcoholism there may be an irregular hallucinatory agitation, sometimes combined with paroxysms of rage, in which acts of atrocity may be committed. While the hallucinations above described are subjectively equivalent to perceptions, the patients believing that they are dealing with something objective, this is not true of what Hagen has called pseudo- hallucination x (psychic hallucinations of Baillarger; apperception hallucinations of Kahl- baum; imagination deceptions of Kraepelin). Faces, printed pages, yellow roses, groups of people appear for a moment and vanish, to be followed by others not logically connected with them. They seem to stand before the eyes, but are not at all related to the black field of vision of the closed eyes. Despite their sharp contours and lively colors, the images do not possess the character of objectivity; the patient says he sees them with "inner eyes," not with his "outer eyes." The images come up involuntarily and remain, even when the patient desires to be rid of them; the details of the vision are clear to him without any feeling of internal activity on his own part, nor can he alter the detail by voluntary effort of imagination. Although the objects seen "stand before the eyes," they are not related to any real objects about him. In pseudo-hallucinations of hearing the patients complain that they are "forced to hear internally" (not with their ears) things which they least wish to hear. Obviously, although these psychic states resemble perceptions on the one hand, and lively reproductions of mere ideas on the other, they differ from both. They differ from percepts in that the patients recognize the lack of objective reality (physical) and their independence of the move- ments of the peripheral sense organ concerned; they differ from ordinary reproductions (images, ideas) in that they have greater intensity and are independent of the will. DISTURBANCES OF MORE COMPLEX PSYCHIC PROCESSES. Anomalies of Consciousness as a Whole.— Consciousness is the fact that we have experiences — sensations, ideas, feelings, etc. To understand DISTURBANCES OF MORE COMPLEX PSYCHIC PROCESSES 43 consciousness, therefore, we must understand experience fully. In spite of ages of speculation we are certainly, as yet, only making a beginning in the understanding of experience, in that we are gradually determining some of the conditions under which it occurs. These conditions are (1) partly of the order of physical facts (e. g., light-waves, sound-waves); (2) partly of the order of physiological facts (e. g., processes in sense organs, nerves, and central nervous structures); and (3) partly of the mind itself (e. g., imagina- tion, feeling, volition). As ideas come and go in consciousness we are aware that some of them are more prominent or outstanding than others. We commonly speak of paying attention to these more prominent ideas. Subjectively this promi- nence of certain ideas is, at times, definitely accompanied by a peculiar feeling of "activity," a sense of strain or effort, which is in contrast to the feeling of "submission" (passivity) which accompanies a distracting sensation or memory. When ideas have the prominence just referred to we feel that they are ours in a peculiar sense — that we are doing something with them. In analogy with the visual field, we often refer to these prominent ideas as being in the focal part of consciousness (Apperception of Wundt), while the other ideas are marginal (Perception of Wundt). Thus according to Wundt, "Perception" (not Wahrnehmung) denotes the mere appearance of a content in consciousness, while "Apperception" denotes its reception as a content which is being related definitely to other facts — in a word, which is being thought about. While no sharp line can be drawn between "Apperception" and " Perception" in Wundt's sense, still there can be no doubt that in the extremes the difference indicated exists. By the mind we usually mean not simply the abstract state of consciousness or the total content or field of consciousness at' any given moment; we include in it also that unity with past experience through which the present moment has a meaning and value, dependent on the whole education of the individual which makes it truly personal. When we distinguish between the activity of the mind (Bewusstseinstiitigkeit) and the content of the mind (Bewusst- seinsinhalt) we should recognize that an abstraction is being made between two aspects of every idea which have no significance apart from one another. In the central neurones changes take place which permit the calling up of memory pictures in simple and complex groups. The totality of memory pictures possibly revivable is what is designated as the contents of the mind. This totality of possible memories is divisible into three parts: (1) That which refers to the external world; (2) that which refers to the body or soma; and (3) that which refers to the personality of the individual. Wernicke has given to these three parts of the mind's contents the names allopsyche, somatopsyche, and autopsyche. The allopsyche, or portion of the mind's contents which concerns the exter- nal world, is made up of memories of concrete things, the result of sense impressions, their combination into perceptions, and the shorthand epitomes of these which we call concepts and notions. The allopsyche of an individual will depend then largely upon his sense organs; that of the congenitally blind will differ greatly from that of the congenitally deaf, and that of the anosmic will be wholly other than that of the ageusic. Given brains of equal birth, the allopsychic contents will vary quantitatively according as the bearer is a resident of a city or a lonely shepherd or backwoodsman, or may differ qualitatively with the environment (e. g., tropical or arctic). 44 DISEASES OF THE NERVOUS SYSTEM The somatopsycke or portion of the mind's contents which concerns the body consists of all the memories which represent residues of previous visceral, muscular, fascial, and cutaneous sensations. In all probability the so-called "local sign" which accompanies the exterior sensations is to be counted as a part of the body consciousness, the local sign of a visual sensa- tion representing, for example, an "organ sensation" of the retina (Wernicke). Here the allopsyche and the somatopsyche overlap. The somatopsyche depends largely upon the condition of the viscera, and the tendency to-day is to relate the hypochondriacal symptoms of mental disease to anomalies of visceral sensations. It is probable that in every allopsychic sense perception the somatopsyche plays a part; indeed, this somatopsychic participation may be the main difference between a perception and a revived image of memory, for in the perception an organ sensation (local sign, feeling tone) is present while it is absent in the memory pictures (Wernicke). The various projection fields for the somatopsyche must be intimately con- nected with one another by associative neurone systems. The connections of the memory pictures concerning the body are much more intimate than those uniting the memories of concrete things of the external world on account of the unalterable relations of the different parts of the body as contrasted with the continuous changes in the world outside the body. In sleep the impressions from the external world cease to affect the brain, although bodily impressions are still entering it. The external world is at times cut off; the body is always there. When the body is undergoing marked changes, as at puberty, the climacteric period, there must be a marked alteration in the character of the afferent impulses from the viscera. Is it any wonder, then, that disturbances of somatopsychic consciousness should tend especially to prevail at such periods? The relative constancy of bodily sensations, the continuity of the somato- psyche, as compared with the variety of sensations from the external world and its discontinuity, give rise in each individual to a conception of unity, of indivisibility, of the body consciousness (primary ego of Meynert). The autopsyche or portion of the mind's contents which concerns the per- sonality or individuality is something built upon the allopsyche and the somatopsyche which serve as its foundations. The autopsyche or conscious- ness of personality includes all the mental possessions and acquisitions result- ing from instruction, culture, and education, the influence of the family and of the social milieu. Speech and written language play an important part in its development. School knowledge is among the early acquisitions of the autopsyche; later on come all the experiences peculiar to the individual. The interest in work, in family, in friends, and in other people belongs here. The development of the autopsyche depends largely upon the kinds of allo- psyche and somatopsyche which form its foundations; as Wernicke puts it, "consciousness of personality is a function of the consciousness of the ex- ternal world and of that of the body. . . . The man with sharp senses and strong body must develop a mental personality different from that of a man with dull senses and a weak body." An individual's own estimate of his place in human society depends upon the state of his autopsyche. Among the striking anomalies in this domain may be mentioned ideas of grandeur or of self-depreciation, ideas of reference and delusions of per- secution. DISTURBANCES OF MORE COMPLEX PSYCHIC PROCESSES 45 There seems to be no doubt that the somatopsyche, the allopsyche, and the autopsyche are, to a certain degree at any rate, localizable; or, more exactly, their physiological correlates appear to be to some degree localizable in the cerebrum. Clinical and pathological studies of dementia paralytica, of cerebral arteriosclerosis, etc., show us how the autopsyche, the allopsyche, and the somatopsyche may separately or successively become involved. Circumspection; Confusion; Unconsciousness. — In the normal awake state there exists a certain equilibrium in perceptions, ideas, and feelings, the external manifestation of which is known as circumspection or presence of mind (Besonnenheii of German writers); here the mind is calm and col- lected with its faculties ready at command. It is the opposite of mental con- fu.non (V erwirrthelt of German writers) or incoherence, in which ideas are jumbled and chaotic, the mind perplexed or bewildered, the speech aimless or unintelligible, the acts disconcerted. By unconsciousness is meant a state in which the psychical powers are wholly in abeyance (dreamless sleep, pro- found narcosis). Attempts have been made to distinguish various grades of pronounced lowering of consciousness, and references will be found to a series of states designated in order as somnolence, sopor, coma, and car us. States of Psychical Cloudiness or of Clouded Consciousness; Mental Fog; Twilight States; Automatism. — By mental fog, psychical cloudiness, or a twilight state (Damme rzustdnde of German writers) is meant a condition in which there is diminution of clearness of consciousness or a loss of memory for a part of past experiences or both together. Such mental fog is often met with in epilepsy and in hysteria. In epileptic mental fog there are often fluctuations of consciousness intensity, partial loss of power of re- calling the past, alterations of mood and false identification. In hysterical mental fog we meet with the so-called monoideic and polyideic somnambulisms and fugues. In somnambulism an individual thinks and acts in an odd way, different from that of other people, while he is in some way like a person asleep. During a monoideic somnambulism the patient acts as though in a dream, but the phenomena of the dream are most perfectly and intensely developed. In fugues (flights or ambidatory automatisms) we have to deal with the hysterical mania for running away. During the abnormal state a certain idea or train of ideas develop to an exaggerated degree (attempt to elude capture; desire for travel, etc.), and lead to the flight. At the same time other thoughts which would normally counteract this idea or train of ideas appear to be suppressed; the patient may forget his name, his family, his social position, or, in other words, his ordinary personality. After the fugue is over and circumspection returns the patient has forgotten many or even all of the events of the flight, and also the ideas which dominated him during it. Through hypnosis it is sometimes possible to reproduce the mental state of the fugue artificially, and so to study it at will. Intermediate between fugues and monoideic somnambulisms are the so-called polyideic somnambulisms. These are characterized by the multi- plicity of the ideas that fill them. Instead of the one idea or event of the monoideic type, we see evidence of the existence of a series of ideas succeed- ing one another in the somnambulic state, ideas which pertain to some strong feeling which develops independently of the rest of consciousness. Where still larger systems of ideas and feelings develop independently we get the mani- festation of what are known as double personalities or multiple personalities. 46 DISEASES OF THE NERVOUS SYSTEM Twilight states are usually temporary, but they may last for varying lengths of time; they may last for weeks or months. The cessation of the state is, as a rule, sudden, the patient waking as though from sleep. Indeed, sleep seems to be the physiological paradigm of a twilight state, dreams being the analogue of the psychical activity, but differing from the consciousness of the twilight state in that usually they are unaccompanied by motor reactions. Disorientation. — Many patients are not well oriented as to their own persons and their spatial and temporal relations. For differential diagnostic pur- poses it is very important to determine the presence or absence of certain other symptoms at the same time orientation is tested, especially anomalies of mood, ideas of persecution and hallucinations. A few simple questions along with those concerning orientation may quickly give the clue to the existence of a hallucinatory confusion, of a paranoid state, or of some other well characterized type of mental disorder. Especially important for the general practitioner is the valuation of the syndrome in which disorientation as regards time and space is combined with so-called pseudo-reminiscences, in which the patient narrates long tales of recent events as though perfectly true, which on inquiry are found to have no basis in fact (Korsakow's syndrome, polyneuritic psychosis). Anomalies of Attention. — The importance of disorders of attention in psychiatry is coming to be very generally recognized. The power of directing thought toward a definite task (Aufgabe) (vigility}, and of maintaining this task despite intercurrent stimuli (tenacity}, are essential in all intellectual operations. We meet with most variable ability to direct and maintain the task, some being able to do this easily, while others are easily distracted. The greater the distractibility the more dirigible from without, the less thorough is the intellectual work. The term hyperprosexia is by some reserved for the pathological persistence of a task in which the mind is concentrated upon certain abnormal ideas or sensations (hypertenacity), while aprosexia is defined as a state in which there is inability to set or to maintain a task (e. g., in imbecility). There is both hypovigility and hypo- tenacity. Some writers use the word hyperprosexia to indicate a state in which there is increased tendency to change the task set (hypervigility) with diminished tenacity. It would be well if psychiatrists would agree upon the definition of these terms, as the different sense in which they are employed leads to much confusion. Examination of the Recording Faculty. — For testing the recording fact/If//, which depends in large part upon attention, much simpler methods must be used in medical practice than in experimental psychological examinations, and we have to thank Ranschburg1 and Boldt2 for supplying us with such simple methods. It is necessary to test the recording faculty in several dif- ferent domains, and most experiments consist of acoustic and optic tests. Thus, in one group of experiments the acoustic word-memory, using the principle of idea associations, may be tested. The patient memorizes fifteen pairs of words, of which five represent customary word compounds, like dog- kennel, chair-leg; five according to the laws of causality (spatial and temporal coincidence), like fish, pond; day, night, etc.; and five according to the prin- ciple of similarity of sound, like wound, wonder; die, dynasty. In another 1 Monatsschr. f. Psychiat. u. NeuroL, Berlin, 1905, ix, 241 to 259. 2 Ibid., 1905, xvii, 97 to 115. DISTURBANCES OF MORE COMPLEX PSYCHIC PROCESSES 47 group of tests the memory of persons is tried by using twenty-five portraits, from which the patient is to recognize five. In a third group the memory for colors may be tested. Many colored skeins of red, blue, green, and yellow wool are shown and a definite example of each is to be recognized. In a fourth group the orientation memory is tested. One shows the patient a chart containing six simple geometrical figures, exposes it for twenty seconds to permit of certain perception, and after a time the patient is required to pick out these six figures from a chart containing twenty or twenty-two figures. In a fifth group the memory for nonsense words is tested, five pairs of words being chosen, e. g., lum, rar; grat, smor. In a sixth group of tests the memory for names is tried. The patient is shown five photographs and the name and surname given. Later on the patient picks out these five photo- graphs from a group of twenty-five and tries to give correct name and sur- name. Lastly, in a seventh group the memory for numbers is tested. Some number is given to each one of the five fingers, and later on, naming each finger, he is asked to give the corresponding number. Suitable methods for testing the recording faculty for touch sensations, smell, and taste will prob- ably later be worked out. The reproduction is best tried shortly after the perception (five or fifteen minutes) and again after twenty-four hours. The recording faculty consists of two factors, namely, perception and reproduction. Of course, where perception is deficient there can be no reproduction later. One makes sure, first, that the task is correctly under- stood. The patient is warned not to try to reproduce repeatedly in his mind the things perceived, for even in normal persons the test turns out less favorably later when such efforts are made. The first reproduction is permitted after five minutes have elapsed, the second after fifteen minutes, and twenty-four hours later the third test is made. The reproduction at the end of twenty-four hours may in normal persons be much better than that at the end of five minutes, but in patients with injured recording faculty this is not the case. The recording faculty appears to be the one of the mental powers first and most seriously to suffer in dementing processes. Injury to the recording faculty as manifested in loss of memory for most recent events never exists long alone; there are added to it very quickly other characteristic symptoms of mental deterioration. The recording faculty is most efficient in childhood especially between the twelfth and the fourteenth years of life. When the recording faculty begins to be impaired it seems to be the mem- ory for numbers which goes first. As Kraepelin has emphasized, studies of this recording faculty have drawn the attention of clinicians to a group of anomalies previously entirely unknown to us, viz., (1) the quick fading of perceptions, and (2) the slow development of perceptions, both of which appear especially to favor the origin of memory falsifications. Anomalies of Ideation. — Great importance attaches to the examination of the processes of ideation ; that is, to the formation and association of ideas. Ideation may be disturbed on the formal side, or there may be falsification of the content of ideas. Of the formal disturbances of association may be men- tioned: (1) Anomalies in velocity; (2) anomalies in the order of association or mode of reaction; (3) anomalies in the intensity and duration of ideas; (4) anomalies in comprehension or apperception; (5) anomalies in so-called identical reproduction (memory) ; (6) anomalies in so-called original pro- duction (phantasy). The falsification of content of ideas is manifest in the production of the so-called insane ideas or delusions. 48 DISEASES OF THE NERVOUS SYSTEM Anomalies in the Velocity of Association; Flight of Ideas; Thought Inhibitions; Stupors. — The association of ideas may be pathologically accelerated or pathologically retarded. Even in health there seems to be an acceleration of the velocity of association during excitement, especially during joyful excitement. A feebler associative impulse suffices to awaken the memory, to raise it, so to speak, above the psychic threshold. In maniacal states we meet with a peculiar form of association known as fight of ideas (Ideenfiucht of the Germans), which is often associated with the form of motor agitation known as pressure of activity and accompanied by marked gesticulation and rapid speech (logorrhcea). In a careful study of the flight of ideas, however, it is found that we have to deal less with acceleration of association than with an alteration in the mode of reaction. The quicker thinking of the maniacal patient seems rather due to the fact that in the same time unit more different objects pass through consciousness than in normal states (Liepmann). In the healthy person ideation is dominated by some principal idea, while in mania the process of association is not controlled by such a dominant idea. One of the most striking characters of the associations in the so-called flight of ideas is the frequent change of direction of ideation. In normal man the kind of reproduction of ideas and the duration depend not only upon the reproduction tendency present in the individual, but also upon the effect of concentration upon the task set. Consciousness is, in a way, set, determined, or prepared in the sense of a specific task. In mania the task set has but little effect upon the process of association as compared with healthy states. The healthy man goes only very gradually from one ideational direction to another and tends to remain for a longer time within the confines of the idea made dominant by the task set. The healthy man, it is true, may for a short time experience rapid associations frequently changing in direc- tion, the quality of the association then being superficial, like those seen in flight of ideas ; but he is incapable of so continuing to associate for any length of time, whereas the characteristic of flight of ideas is the continuance of such associations until the physical strength is exhausted. At bottom the disturbance known as flight of ideas must be largely a dis- turbance of attention. The main change in the attention seems to be an increase in the capacity for directing the thought quickly and energetically to single ideas (hypervigility), and also away from them again (hypotenacity). To explain the abundance of ideas reproduced, however, -it is necessary to assume also an alteration of the power of reproduction, permitting the appearance in consciousness of a wealth of lively ideas capable of being easily replaced one by another (Isserlin). Psychiatrists distinguish a primary flight of ideas (e. g., reminiscence flight in neurasthenic and hypochondriacal states and in the exaltation of mania) from a secondary flight of ideas due to quickly changing hallucinations and delusions; in the latter case the idea flight is not a new disease symptom, but is secondary to the affective excitation called forth by the hallucinations or delusions. When the associations run unbridled by a dominant idea, as they do in the marked forms of idea flight, there is an ever-increasing inability to follow anything like a normal train of thought (secondary incoherence). Pathological retardation of association (thought inhibition) may also appear, either as a primary phenomenon or as a secondary symptom. When pro- nounced it leads to the condition known as stupor. Such slowed association is nearly always • associated also with motor DISTURBANCES OF MORE COMPLEX PSYCHIC PROCESSES 49 inhibition in which the so-called voluntary movements are slowed or absent altogether. The patient is unable to complete the series of associations between the initial idea and the terminal motor idea. Speech becomes more and more slowed until there may be complete mutism. The various voluntary muscles of the body may be held rigidly (as in catatonic rigidity). As examples of primary stupor may be mentioned (1) the so-called excitation stupor which appears in the slowly developing conditions of cere- bral excitation, and (2) the stupors which appear in the course of various intoxications. Unless the history is known .in such cases it is sometimes difficult to tell whether one is dealing merely with an inhibitory process or with actual defect (dementia), as secondary stupor may be designated the form which accompanies or follows various states of psychic depression. An emotional shock or a paroxysmal anxiety condition may call forth a severe secondary thought inhibition. A special form of secondary stupor due to delusions and hallucinations accompanied by strong affective states is met with in certain conditions of catatonic rigidity (pseudo-stupor of Westphal). The so-called waxy flexibility (flexibilitas cerea) may be regarded as a part of the general inhibition of association. For actually measuring the velocity of associations (determination of reaction times) psychologists have provided us with a number of very exact methods. Many of these are too complex for use with nervous and mental patients, and experience teaches that the ordinary "answer method" with the aid of a stop-watch which marks one-fifth of a second is sufficient for most purposes. The examiner explains the method to the patient, calls the test word, and at the same moment starts the stop-watch; the moment the answer is heard he notes this and the time required. In collecting a series of reaction times it is well to establish a middle position and a middle zone of times, according to Kraepelin's suggestion. Anomalies in the Order of Association or Mode of Reaction. — Perhaps most progress in recent years has been made in the study of the mode of reaction in association tests. Psychologists have taught us that even in health, associations of different types occur. A study of diseased conditions reveals marked deviations from the normal modes of reaction. Anyone working in this field should early inform himself of the researches of Kraepe- lin, Aschaffenburg, Jung, Sommer, and Isserlin. It is customary to classify the kinds of association as follows: A. Sense of test words correctly understood. (a) Internal associations. (1) Associations of coordination and subordination. (2) Predicative associations. (3) Causality associations. (6) External associations. (1) Associations of spatial and temporal co-existence. (2) Identities. (3) Speech reminiscences. B. Sense of test words not understood. (c) Test words acting only through their sound. (1) Word sup- plements. (2) Sound associations and rhyme associations. (A) Intelligible. (5) Nonsensical. (d) Test words acting only by setting free reactions. (1) Repetition of test word. (2) Repetition of earlier reactions without sense. (3) Associations for words used earlier. (4) Reactions without recognizable connection. VOL. vn.-^-4 50 DISEASES OF THE NERVOUS SYSTEM It is also important to note how many of the reactions are more objective in nature and how many of them are more subjective (egocentric). A word of explanation as to the meaning of some of the terms used above seems desirable. By an internal association is meant one directed toward the sense of the test word, while an external association is one dependent upon custom, habit of speech, and sound relation. In the predicative associations there is some affirmation or assertion regarding the object of the test word. In the causality associations there is a relation of cause and effect. By word supplementation one means only such reaction words as, taken with the test word, make together an indivisible word. Such reactions belong, of course, to clang reactions in the wider sense. A distinction is made between mediate association and immediate (Aschaf- fenburg). In the former the only way one can understand a connection between the test word and the reaction is by assuming some intermediate member of an association series. As a rule, such intermediate member turns out to be a clang association for the test word, while the relations of the reaction word to the intermediate member may be any one of the forms of association mentioned. It is customary to designate instances in which more than sixty seconds elapse before an answer is given to the test word as "faults." Reactions in which there is simply a repetition of the test word are in a class by themselves. It is well also to count up the number of perseverations and repetitions which occur. By perseveration is meant a reaction in which there has been evidently a connection on an earlier test or reaction word instead of to the actual test word given; by repetition is meant a reaction in which the test or reaction word immediately preceding recurs. Discursive associations should also be especially noted (IVeiterschweifen of Isserlin). By this is meant a spontaneous continuation of the association. Such further association may be intelligible or nonsensical. Special attention should be paid to the instances in which the test word is repeated by the patient. When this is a marked feature in a case it should be determined whether it is due to anomalies of comprehension from marked distractibility, in which the attempt to concentrate leads to repetitions, or whether it is dependent upon inability to draw upon the reproductive ele- ments sufficiently, that is to say, is due to a lack of associated ideas (as in the thought inhibition of depressive states). A patient will often give the clue himself, since he may mention, on the one hand, that nothing occurs to him, or, on the other, that so many things pass through his mind that he repeated the test word in order to answer correctly. The two types are further distin- guishable by the fact that, in the one, reproductions often in large number appear immediately after the repeated test word, while in the instances due to thought inhibition associations occur only after quite a pause, and often only after several slow repetitions of the test word. In the selection of a list of test words certain principles should be borne in mind, including (1) the principle of the uniform stimulus, (2) limitation of total number of tests so as to avoid fatigue, (3) selection of words which will bear upon a whole series of different groups of ideas. Sommer has prepared three lists, one containing adjectives pertaining to the different sense domains (including light arid colors, extent and form movement, feeling, temperature, sound, smell, taste, etc.), the second a list of words referring to ideas of objects, the third list including designations DISTURBANCES OF MORE COMPLEX PSYCHIC PROCESSES 51 for things which are associated with affective states or actual terms for such affective states, and also words referring to conditions of the intellect, consciousness, and social affairs. TEST WORDS FOR ASSOCIATION EXPERIMENT I. I. 1. Light. 2. Dark. 3. White. 4. Black. 5. Red. 6. Yellow. 7. Green. 8. Blue. II. 1. Bright. 2. High. 3. Deep. 4. Thick. 5. Thin. 6. Round. 7. Angular. 8. Sharp. III. 1. Quiet. 2. Slow. 3. Quick. rv. 1. Rough. 2. Smooth. 3. Solid. 4. Hard. 5. Soft. V. 1. Cold. 2. Tepid. 3. Warm. 4. Hot. VI. 1. Low. 2. Loud. 3. Shrieking. 4. Yelling. VII. 1. Fragrant. 2. Stinking. 3. Mouldy. VIII. 1. Sweet. 2. Sour. 3. Bitter. 4. Salt. IX. 1. Painful. 2. Ticklish. 3. Hungry. 4. Thirsty. 5. Nauseating. X. 1. Beautiful. 2. Ugly. TEST WORDS FOR ASSOCIATION EXPERIMENT II. XIII. XV. XVII. 1. Head. 2. Hand. 3. Foot. 4. Brain. 5. Lungs. 6. Stomach. XII. 1. Table. 2. Chair. 3. Mirror. 4. Lamp. 5. Sofa. 6. Bed. 1. Stairs. 2. Room. 3. House. 4. Palace. 5. Town. 6. Street. XIV. 1. Mountain. 2. River. 3. Valley. 4. Sea. 5. Star. 6. Sun. 1. Root. 2. Leaf. 3. Stem. 4. Flower. 5. Bud. 6. Blossom. XVI. 1. Spider. 2. Butterfly. 3. Eagle. 4. Sheep. 5. Lion. 6. Mankind. 1. Man. 2. Woman. 3. Girl. 4. Boy. 5. Children. 6. Grandchild. XVIII. 1. Peasant. 2. Citizen. 3. Soldier. 4. Pastor. 5. Doctor. 6. King. TEST WORDS FOR ASSOCIATION EXPERIMENT III. XIX. 1. Disease. 2. Unhappiness. 3. Crime. 4. Need. 5. Persecution. 6. Misery. XX. 1. Happiness. 2. Reward. 3. Kindness. 4. Health. 5. Peace. 6. Joy. XXI. 1. Alas! 2. Oh! 3. Fie! 4. Ha! 5. Hello! 6. Ouch! XXII. 1. Anger. 2. Love. 3. Hate. 4. Light. 5. Fear. 6. Fright. XXIII. 1. Impulse. 2. Will. 3. Command. 4. Wish. 5. Activity. 6. Decision. XXV. 1. Consciousness. 2. Sleep. 3. Dream. 4. Recollection. 5. Memory. 6. Thoughts. XXIV. 1. Reason. 2. Insight. 3. Wisdom. 4. Intention. 5. Knowledge. 6. Stupidity. XXVI. 1. Law. 2. Order. 3. Custom. 4. Right. 5. Justice. 6. State. 52 DISEASES OF THE NERVOUS SYSTEM Practice has shown that it is better not to use the test words in groups, as Sommer first recommended, but to make the series so that single words of different groups follow one another. Jung has especially emphasized the importance of this on account of the emotional relations of certain of the test words. Experience with these association tests soon permits one by their aid to differentiate quickly among the great groups of psychotic symptoms. Another advantage of systematic monthly association tests consists in the ability to follow the exacerbation or retrogression of psychopathic symptoms. In valuing the results of association tests one should familiarize himself, first, with a large material obtained from healthy people. Educated people show, on the average, a more "superficial" type of reaction than uneducated people, the latter reacting more to the sense of the test word than the former. Differences in individuality determine also certain important variations in association. Jung and Riklin distinguish two main types: (1) Objective types, and (2) subjective types with egocentric adjustment. To the objective types belong those persons by whom the test word is understood objectively, either according to its sense or as a speech stimulus, while to the subjective types belong (a) the so-called "constellation" types, in which personal experi- ence (idea complexes) with strong feeling tone appear in the associations, and (6) the "predicate" types, which present lively, subjectively valued ideas. The reaction time of normal persons varies greatly according to the age, education, and individuality. The more phlegmatic and the intellectually feebler individuals show, as a rule, longer reaction times. The quality of the association is an important factor in its duration; thus the more complicated an association is psychologically the longer the reaction time. The associa- tions which are most used in daily life are those with the shorter reaction times, a fact which explains the velocity of "external" associations as con- trasted with "internal" associations. One of the most important results of association tests is the bringing of the proof of the delay in reaction time in associations to which idea complexes with strong feeling tone are attached. Association tests in the melancholic states of manic-depressive insanity reveal a marked prolongation of the reaction time and apparently a char- acteristic change in the content of the associations. There appears to be a limitation to idea change. The reaction type is usually predominantly ob- jective. Even in the very delayed associations when the reaction is recorded, it is as a rule found to correspond in sense to the test word. In the maniacal states of manic-depressive insanity the striking features are a "flattening" of the associations and the replacement of associations due to the sense of the test words by associations which depend upon custom, speech, and mere sound relations (clang associations). The frequency of discursive associations (Weiterschweifen) in mania has been pointed out by Isserlin. As in flight of ideas in general the reaction times are not shorter than normal; indeed, they are sometimes really longer, although in maniacal states one does meet perhaps with a greater number of short reaction times than in health. The most characteristic phenomenon in mania is the greater number of single ideas produced during a given time — many more than one ever meets with in health. It is the extraordinarily frequent change of direction of the ideas which is so striking. Healthy persons are incapable of associating so quickly with such frequent change of direction and in such a "superficial" manner as is characteristic of the idea flight of maniacal states. DISTURBANCES OF MORE COMPLEX PSYCHIC PROCESSES 53 Very recently progress has been made in the study of associations in the so-called mixed slates of exaltation and depression, in which certain of the signs of mania are associated with certain of the signs of depression. One tries to find out whether the reaction time is prompt or delayed, whether the type of reaction is according to the sense of the test words or superficial, whether the direction of the ideas is changed frequently or rarely, whether there are many or few perseverations and repetitions, whether the form of the answers indicates a precise reaction or a vague "talking around the subject," whether the feeling tone is positive or negative, and whether or not egocentric relations, faults, and test- word repetitions are prominent (Isserlin). In the "mixed states," egocentric relations may be extremely frequent. Test-word repetitions tend also to be especially common in these mixed states. In view of the help which comes from a study of the results of association tests, some physicians seem inclined to overestimate their value. It should be borne in mind that they reflect only one side of mental life, and that one must not neglect other psychological methods of examination. The general practitioner has not yet formed the habit, however, of resorting to association tests, and to him the method can be heartily recommended as a means of extending the anamnesis. Especially in the differential diagnosis of manic- depressive insanity from dementia prsecox the method will be found helpful. If one bears in mind the characteristic signs of inhibition and excitation revealed in the patient's entrance upon the task of association in manic- depressive insanity, and compares therewith the refractory, perverse behavior with regard to the task characteristic of the patient suffering from dementia praBcox, and observes, further, the stereotyped replies and repetitions or per- severations which may seem to disregard the test words, the paralogia, and mannerisms which come out during the association tests, one will find the method one of the best available in distinguishing these two types of psychosis from one another. Even in cases where strong inhibition simulates apathy and dementia the association experiment helps to differentiate. If, in spite of long reaction times, we see an effort to understand the sense of the test word, we can, as Isserlin emphasizes, make the diagnosis of manic-depressive insanity even when the change of direction of the ideas is only moderate and there seems to be relatively little affectivity. In dementia praecox the patient reveals himself by the reaction time (ordinarily not so evenly prolonged as in the depression of manic-depressive and, when not normal, more lawlessly desultory) and by the apathetic or perverse behavior toward the task set. The association tests also help in differentiating the depressive states of manic-depressive insanity from some forms of hysteria. In the latter disease it is especially the emotional phenomena, the signs of the idea complexes emphasized by feeling (gefiihlsbetonte Komplexe} which are characteristic. In manic-depressive insanity the inhibition is demonstrable aside from the slowing effect upon the reaction time of such emotive complexes, and, further, the associations in general in this psychosis present a much less capricious and variable appearance. It must not be forgotten, however, that hysteria and manic-depressive insanity may be combined in the same patient. Anomalies in the Associative Connection of Ideas (Incoherence or Dissocia- tion).— Normally, the course followed in associations from the initial idea to the terminal idea is a well-regulated one, depending upon some dominant or superior idea. In many psychoses this normal connection of ideas in the associative processes is disturbed. The initial idea may be followed by a 54 DISEASES OF THE NERVOUS SYSTEM second idea which stands in no recognizable relation to it, an anomaly designated by psychiatrists as dissociation or incoherence of association. If a patient be asked what time it is, and she answer "fox," a severe disturbance of this sort is manifest. In milder cases the disturbance is manifested by the fact that the patient continuously loses the thread of thought. When a patient is disoriented as to time, place, and personal relations, along with general incoherence of association, the movements and speech of the patient being correspondingly disturbed (motor incoherence), the condition is technically known as confusion (Verunrrtheit of the Germans). Very often incoherence and confusion are used as synonymous terms. It is customary to distinguish a primary from a secondary incoherence, the former appearing autochthonously, independent of any other psychopathic symptom (e. g., in the so-called acute hallucinatory confusion or amentia), the latter as a sequel to other psychopathic phenomena (e. g., flight of ideas, hallucinations, strong emotions, dementias, etc.). The secondary disso- ciation or incoherence is, therefore, common to many severe mental dis- turbances. The process of loosening or dissociation has been designated sejunction by Wernicke. When a dissociation occurs suddenly and lasts only a short time, there result lacunae in consciousness (the so-called psychic eclipses or deliquia of L. Meyer), which may form the starting point of manifold disturbances of the content of the ideas. The differential diag- nosis of the different forms of incoherence is often very difficult. In mild instances of general incoherence a peculiar symptom is sometimes met with, known as pathological notions (Einfalle of the Germans). In the midst of a well-ordered and often extensive thought series, there comes sud- denly and apparently without reason an idea or complex of ideas which stands in no connection whatever, by external or internal association as far as can be seen, with the former. The patient betrays the presence of such pathological notions by a sudden word or a peculiar gesture. Anomalies in the Intensity and Duration of Ideas. — Instead of the ordinary course of associations, single ideas or idea complexes may attain to abnormal strength and be very frequently repeated in consciousness. Here belong the exaggerated or hyperdynamic ideas (iiberwerthige Ideen of Wernicke) and the imperative ideas (Zwangvorstellungen of Krafft-Ebing), sometimes known as obsessions. Such ideas arise especially in individuals who are constitutionally psychopathic at times when they are mentally or physically exhausted. They are especially characteristic in the so-called psychasthenic states (Janet) . Wernicke distinguishes between hyperdynamic ideas, imperative ideas, and autochthonous ideas. The exaggerated or hyperdynamic ideas are char- acterized by the fact that the patients do not recognize them as intruders in consciousness; on the contrary, the patient regards them as the expression of his innermost nature, and in battling for them he is struggling for the maintenance of his own personality. They are, nevertheless, often felt as troublesome, and the patients frequently complain that they can think of nothing else. Imperative ideas or obsessions, however, are recognized as unjustifiable ideas, and are often spoken of as absurd. The autochthonous ideas have the attention forcibly directed toward them and are felt as trouble- some intruders. Wernicke separates them from imperative ideas, since the latter are not regarded as foreign to the personality of the patient, and hence are not serious for the mental life of the patient as are autochthonous DISTURBANCES OF MORE COMPLEX PSYCHIC PROCESSES 55 thoughts. The closest relations between hallucinations and autochthonous ideas have been pointed out by various psychiatric writers; indeed, transitions between the two sometimes may occur, the hearing of voices being sometimes preceded, for example, by a stage in which autochthonous thoughts are present. Many of the imperative ideas or obsessions are combined with marked affective disturbances, giving rise to the so-called phobias; thus, a patient may fear to cross an open place (agoraphobia), may fear shut-in places (claustrophobia), may fear contamination (mysophobw), may fear disease (nosophobid) , or may be afraid of everything (panphobia). When the same idea comes up over and over again the patients may be led to stereotyped methods of expression. The patient may answer a first question correctly, but may tend to give the same answer to various other questions subsequently put (perseveration). In contrast with hyperdynamic ideas are the hypodynamic ideas. Certain experiences which in normal life may be well remembered and attended to are lost sight of or do not seem to have their normal value in the patient's mental life. Anomalies of Reproduction or Memory (Hypermnesia; Hypomnesia; Amnesia; Paramnesia).— The power of reproduction may be pathologically facilitated (hypermnesia}, diminished or retarded (hypomnesia), abolished (amnesia), or perverted (paramnesia) . Hypermnesia is often met with in exalted or maniacal states and is usually associated with abnormal affective phenomena. Past acts, feelings, or ideas appear vividly in the mind, which in its natural state may have wholly lost the remembrance of them. Ordinary individuals sometimes experience hypermnesia in sleep or in certain unnatural conditions, e. g., under the influence of drugs (alcohol, morphine). Weakened memory or hypomnesia may betray itself in the increased length of time it takes to recall an image or in the vagueness of the reproduction. In outspoken pathological diminution or destruction of the power of memory (amnesia) there is complete inability for reproduction of a part or the whole of past experiences. The term amnesia is by some reserved for complete loss of memory for a certain period; for example, that of dreamless sleep, of epileptic coma, of hysterical somnambulism, and the like. When the amnesia concerns not only the period of the pathological condition itself, but extends to a longer or shorter time preceding the attack, it is called retrospective or retrograde amnesia. The term antero- grade amnesia has been used to designate the defect of memory which extends to occurrences of the period subsequent to the termination of the clouding of consciousness, a condition doubtless due to the depression of the recording faculty and the injury to the associative processes fol- lowing the period of mental fog. When in the period subsequent to the termination of the mental fog the patient still remembers certain experi- ences, but soon after forgets them entirely, the condition is spoken of as retarded amnesia. Among the most interesting amnesias are those of the alternating personalities of hysterical patients, in which two, three, or more alternating states of consciousness develop, of which the first and third and second and fourth may stand in close associative connection with one another, while in the second and fourth states complete amnesia for the experiences of the first and third exists. 56 DISEASES OF THE NERVOUS SYSTEM The amnesia may be partial, involving only the events of the recent past and not those of the distant past. Especially in progressive failure of memory, such as that met with in dementia senilis and in dementia paralytica, there is a gradual loss of memories, beginning with the most recent ones and involving gradually those of the past (law of regression of Ribot). Circumscribed amnesias in special domains are met with very frequently in focal diseases of the brain. Thus, when optic memory images can no longer be called up, the condition is known as mind blindness (Seelenblindheit of the Germans). The mind-blind person may still have intact visual sensa- tions, but he is unable to recognize what he sees because his visual memories are lost or, at any rate, cannot be awakened in the ordinary way by retinal stimuli, since the association between the primary optic centres in the cortex and the areas concerned with visual memory are interfered with. Two great groups of cases can be distinguished from one another. In the first group we have to deal rather with a disturbance in optic perception than in optic memory. In this group belongs the so-called apperceptive form of mind blindness of Lissauer, which corresponds to the so-called cortical blindness (Rindenblindheit of Munk). In this group the principal disturbances are hemianopsia, diminution of visual acuity, and disturbance of color sense. Stereoscopic vision is also sometimes involved. On the psychic side there is usually an incapacity for orientation in space. There need not, however, be any marked disturbance of the visual memory or of the capacity for recognizing ordinary objects. Reading and writing may be nearly intact. The second group of cases includes mind blindness proper, which is less a disturbance of perception than a loss of capacity for the intellectual valuation of retinal images. The condition is spoken of by Lissauer as the associative form of mind blindness. The patient is unable to recognize objects shown him because the visual images do not call up by association the memories which permit their identification, and so they appear to him as strange confusing figures (optic asymbolid). A patient looking at his wife, may know that she is a woman and see the details of her form and clothing exactly, but yet not recognize that she is his wife. If very circumscribed areas in which optic memories are localized or the pathways to them be destroyed, the phenomena of word blindness or of optic aphasia may be met with. In word blindness or alexia there is an incapacity to read, although speech and the understanding of speech may be retained. The power to write may or may not be present. In the former case one speaks of subcortical or pure alexia (probably due to lesion of the associative paths between the visual sense area in the cortex and the sensory speech areas). In the optic aphasia of Freund, a rare condition, objects held before the patient are seen and recognized but cannot be designated, although the patients can otherwise speak well and can find the particular word concerned when the stimulus is awakened through some other sense organ. It appears to follow most frequently upon lesions at the junction of the left occipital and left temporal lobes interrupting the association paths which extend from the two occipital lobes to the centre for word-clang memories. A similar isolated loss of acoustic memorial images is known as mind deafness. The patient may hear everything, but cannot recognize the sounds. The most frequent form met with is that known as word deafness in the sensory aphasia of Wernicke. The patient hears the word, but no DISTURBANCES OF MORE COMPLEX PSYCHIC PROCESSES 57 longer recognizes it and cannot understand it (lesion of the first temporal gyrus on the left side). Here, too, we probably have to distinguish a group of cases in which the disturbance is perceptive and a second group in which it is associative, the latter being sometimes referred to as amnestic aphasia. When tactile memorial images can no longer be awakened we have mind anaesthesia for touch. The patients feel contact, but cannot recognize objects through it. Similarly, there may be a loss of the memorial images for kines thetic sensations. Under the term paramnesia come the falsifications of memory, including what Sully has described as memory phantasms and memory illusions. In the memory phantasms the patient seems to remember things which he has never experienced. The combinations of pure phantasy are regarded as actual experiences. They seem to be due to a loss of critical power, and depend upon enfeebled judgment. Here must be placed the tendency to confabulation and pseudo-reminiscences, so common, for example, in Korsakow's psychosis. By memory illusions the memorial images themselves are falsified, the dis- turbance being due to faulty reproduction and lively fancy or the falsifying influence of a temporary affective state. As Sully puts it, the past now appears in the colors of the present. Such patients may appear to be liars, since they unconsciously distort their experiences in reproduction. A very good example of such illusions of memory is often seen in connection with the uncinate gyrus fits of H. Jackson. A special form of memory deception is seen in the identification of a present situation with one presumably previously experienced. This sentiment du deja vu is one of the most interesting paramnesias met with among psychas- thenics. It seems to be as much a disturbance of perception as of memory. The patient, feeling that impressions escape him, comes to the belief that he is experiencing memories. Methods of Testing Memory. — The tendency among neurologists at present is to treat all memory loss not as a disturbance of a unitary capacity of the brain, but rather as disturbances of a large group of single capacities. It is true that the memory as a whole, that is, the conglomeration of all these partial faculties, may be impaired particularly in some of the psychoses, but in neurological conditions in which circumscribed lesions of the cerebrum are met with we see more often injuries of the partial memory faculties. On testing the memory clinically, therefore, one must use methods which permit us to judge not only of the memory power in general but of the capacity for and fidelity of reproduction in each indi- vidual domain. It is best to begin by testing the memory for fresh impressions or for recent events. One determines a defective power for the immediate acquisition and retention of ideas (recording faculty), and also defective capacity for the acquisition of general and relative ideas (power of abstraction). In addition, it is necessary to test the memory for older impressions or for events which have occurred earlier in the life of the individual, and here one does best to examine the patient's memory for what he has learned at school and to try his power of calculation. In testing school memories, one should have some knowledge of the extent to which the patient has been educated, as obviously the testing of illiterate persons for school memories would be useless. It is advantageous to use a uniform set of questions in 58 DISEASES OF THE NERVOUS SYSTEM order that comparisons of value may be made among the replies received from different patients. It is customary, therefore, to ask the patient to repeat a number of series which in school are learned by heart: for example, the alphabet, the numerals, the names of the months, and the names of the days of the week. Certain national and religious facts which everyone may reasonably be expected to know may also be inquired into. To these questions may be added others regarding well-known facts of geography and history. Normal answers do not necessarily indicate mental normality, since in non-paralytic dementias, for example, school memories are often very well retained. In dementia paralytica, however, there are usually marked disturbances of memory for simple series of letters and numbers. In catatonic dementia there often seems to be a loss of school memories, although this is more often dependent less upon lack of knowl- edge than upon the grotesque irrelevancy exhibited by such account of his strenuous assertion of incapacity, while in maniacal states ignorance may be simulated by the associative discursiveness which the patients manifest. An imbecile may give fluent and correct answers to a number of questions which involve the automatic reproduction of a series of patients in replying to questions, the so-called paralogia. In melancholia the patient may ap- pear to have lost his memory for school knowledge on numbers or names. The solution of the problems themselves is not the only important point. The time taken to solve them and concomitant phenomena of physiognomy and speech should be taken into account. The use of these methods has demonstrated that certain phenomena recur typically in different groups of clinical cases, and Sommer especially recommends the methods for the differential diagnosis of different forms of dementia. Through their applica- tion one obtains not only a more exact insight into the partial functions of the power of calculation, but also can give mathematical expression (where tests are repeated at intervals in the same cases) to the symptoms of periodic variation, of advancing intellectual disintegration, of stereotypism, etc. Falsification of the Content of Ideas (Delusions). — The power of forming judgments and conclusions by means of the association of ideas depends in health upon the existence of certain regular relations between the various memories derived from preceding sensations regarding the body and the external world. Judgments depend, however, not entirely upon one's own personal experience, but upon tradition and upon the ideas dominant in the circle in which one lives at the time. One's own personal knowledge is sup- plemented by certain prevalent beliefs (religious, scientific, political, etc.). On account of the stronger feeling tone which accompanies beliefs their influence upon the power of judgment can scarcely be overestimated. While it is true that men of rich individual experience with strong powers of obser- vation and analysis may attain to a high power of independent judgment; still no one, even the intellectually greatest, remains uninfluenced by belief, for individual experience, no matter how extensive, must be supplemented by beliefs which bridge over the gaps of experience. Everyone is, therefore, liable to make mistakes due to prejudice and superstition, and there is every transition from the mistaken judgments of human beings whom we call normal to the delusions or false judgments of the insane. In both instances the false judgment arises as a result of combinations of ideas which are out of accord with the facts of the so-called external world. The mistakes of the normal man can, however, be corrected by subsequent judgments depending DISTURBANCES OF MORE COMPLEX PSYCHtC PROCESSES 59 upon new perceptions and more correct inferences, but the insane delusion is not amenable to such correction. Even in people who are not insane there may be certain false judgments which cannot be corrected. People brought up in an atmosphere of strong prejudice and superstition may be incorrigible in their beliefs and yet not be insane in the strict sense. Believers in Christian Science, in spiritualism, and the like may form false judgments, but we would hesitate to call them insane. The false judgments are to be regarded as insane delusions when associated with other undoubted phenomena of alienation. Insane delusions are divided into primary delusions and secondary delu- sions. The former usually arise from abnormal states of feeling in connec- tion with a pathological exaggeration of the consciousness of personality. The latter are, as a rule, explanation delusions or attempts on the part of the individual who has passed through a psychosis with injury to his mental processes to explain the changes in his consciousness. In the primary delusions egocentric ideas dominate the consciousness and lead to the formation of false ideas of reference — that is to say, to false ideas regarding the individual and the processes of the external world. Such false ideas may, if there be a decided alteration in the associative mechanism, form the starting point for a permanently developing chronic delusional system (paranoid states). Clinically such individuals may appear to have normal recording faculty, recognition, and memory, but despite thereof manifest fundamental disturbance in the formation of judgments. On superficial examination such patients may seem very intelligent, and one would not suspect them of being insane until one learned from prolonged conversation the falsification of their judgments regarding their own person- ality and their entire lack of disease insight as regards such falsification of the content of their ideas. Temporary and curable delusions may occur in acute psychoses as a symptom of inhibition of normal associations, but the chronic, incurable delusional insanities depend rather upon permanent loss of certain possibilities of association, the patient being unable critically to sift and arrange his judgments as a normal individual can do. Many of the chronic systematized and progressive delusional states begin with a period of psychic eclipse. The patients complain that for some days or weeks their minds have been empty and that they have felt restless. Some go so far as to assert that they must have been anaesthetized or poisoned at the time. In the acute psychoses, especially those accompanying infections and intoxications, delusions are prone to arise as a result of the primary incoher- ence. The mixed-up ideas of the patient lead to peculiar and nonsensical judgment associations. In some cases delusions arise in which a primary associative disturbance cannot be demonstrated, the falsification of content of the ideas here depending upon pathological affective processes. There can be no doubt that illusions and hallucinations are of great importance also for the origin of delusions. This is well illustrated in the so-called acute hallucinatory confusion or amentia; in curable cases the delusions disappear, but where a dementing process succeeds, the hallucina- tory delusions may continue unaltered or may develop farther (Binswanger). In chronic paranoid states the delusions may precede the hallucination and illusions, the latter being the outcome of the former. In the so-called acute hallucinatory paranoia the delusions arise primarily (in contrast with amentia, in which they are more secondary); in this disease the primary (30 DISEASES OF THE NERVOUS SYSTEM suspiciousness of the patient may be followed by hallucinations which convert the suspicions into certainty. Explanation delusions (secondary delusions in the strict sense) occur where pathological states of feeling are protracted (prolonged exaltation or pro- longed depression) and form the basis of the false judgments. The hyperdynamic ideas corresponding to an exalted state may easily lead to delusions of grandeur (dementia paralytica, dementia praecox). Similarly, the hyperdynamic ideas corresponding to the depressed mood of the melancholic and the hypochondriac may become fixed as depressive delusions, which persist even after the pathological mood has disappeared. The expansive (megalomanic) delusions and depressive (micromanic) delusions together make up the primordial deliria of Griesinger. Depressive delusions include the delusions of sin, the hypochondriacal delusions, the poverty delusions, and the delusions of persecution. Delusions of persecution differ from the other forms of micromanic delu- sions in that other people (enemies, persecutors) are held responsible there- for. Sometimes they arise primarily and are connected with abnormal sensations. The feeling of fatigue which sometimes follows the drinking of a glass of beer may excite the persecutory idea that the beer has been poisoned or that someone intended to drug the patient, perhaps in order to do some crime. Still more frequently persecutory ideas arise as a result of hallucina- tions or illusions. Complementary or contrasting persecutory delusions are often associated with delusions of grandeur, the patient assuming that he is being attacked on account of the greatness of his position. Ideas of reference (Beziehungswahri) may be the forerunners of ideas of persecution. The patient refers looks, acts, remarks of other people to him- self without sufficient reason. He thinks he is being influenced or watched or injured by someone else. He may become abnormally jealous (jealousy delusion) or he may get the idea that he is suspected of a crime and that he is to be brought into court (imputation delusion). The patient may attribute the persecution sometimes to definite persons about him, sometimes to invis- ible and unknown enemies. Sooner or later such a patient is likely to become convinced that a great conspiracy has been formed against him. A word must be said about the so-called general delusion of denial (delire de negation generalise of the French). It usually follows delusions of sin, the patient becoming so bad in his own estimation that he identifies himself with Satan. He can atone for this only by eternal punishment, and so comes to regard himself as immortal. Such a patient may think that his body is infinite in size as well as in duration (delire d'enormite). As this leaves no room for'the rest of the world, such patients assert that the world no longer exists and that all men are shadows; even God ceases to exist. When delusions first appear they are usually accompanied by affective states which correspond to the content of the delusion, but after long standing this feeling tone of the delusions may disappear. The mode of onset of a delusion may be sudden or it may develop gradually. Primary delusions tend to have the latter form of development, and are more apt to become fixed; hence the unfavorable prognosis in such cases, as a rule. Fixed delusions are prone to be followed later by a so-called systematiza- tion, the patient adding complementary delusions to the fixed delusion, the new delusion being connected logically with the original false judgment. Such systematized delusional states may last throughout the life of the patient. DISTURBANCES OF MORE COMPLEX PSYCHIC PROCESSES 61 To be distinguished from the delusions above described are the defects in judgment met with in imbeciles and patients, who for some reason or another have had some arrest of development. In such cases the memory pictures are defective and the associative relations among them are fewer than normal; as a result, incorrect judgments are very likely to be formed. As Ziehen puts it, poverty in ideas and in associative connections among them, together with feebleness of judgment, are the essential features of the intellectual defect, both in acquired and congenital feeble-mindedness. All grades of such feeble judgment are met with, from the mildest lack of critical power to the most complete lack of judgment. The former is due to absence of a few complicated ideas and associations, while the latter depends upon absence of the simplest everyday ideas and associations. Imperative ideas and delusions often disappear, but the feeble judgment once established nearly always remains. Anomalies of Affective and Emotional States.— We have referred repeatedly in the preceding pages to the feeling tone accompanying sensa- tions and ideas. Whereas sensations and their memory pictures (the so-called ideas or images) represent the elementary phenomena of consciousness which refer to objects external to a given perceiving subject or personality, the feel- ings, on the other hand, and the affective or emotional states in which they play the essential role represent the more intimately subjective side of experience in that this portion of the content of consciousness expresses the attitude of the individual to objects, etc., in its most fundamental form; that is, in particular, as it bears upon his conduct. In the affective states generally, then, we approach one of the most complex and difficult aspects of the psychologist's problem. The elements of our experience of external objects about which no dif- ference of opinion exists are sensations. In the same sense the elements of the affective side of consciousness include agreeableness and disagreeableness (pleasure and pain of the older psychologists, and positive and negative feeling tones used by physiologists generally); these two, at least, are elementary feelings. Whether Wundt's assumption that there are six directions in which elementary feelings may vary — the agreeable and disagreeable, the exciting and depressing, and the straining and relaxing — be correct or not need not here detain us. Emotions are more complex than simple feelings, in that they contain not merely affective, but, quite as essentially, sensational (perceptional) elements also. The analysis of an emotion, for example, fear, reveals not only a feeling of disagreeableness, but also the sensational factors which represent the object which is feared, together with complexes of kinaesthetic and visceral sensations, the exact nature of which has not yet been discovered. The close relation between emotions and bodily movements is evident. Moods are of the nature of emotions having the same general consti- tution, but, as a rule, they lack definiteness in that the sensational or objective side of a mood is not so frequently one particular object. Moods are, in genera], of longer duration than emotions, and do not so readily express themselves in some definite act which tends to bring the state, as in emotion, to an end. On the contrary, they persist for longer periods as a kind of general affective tone of experience (e. g., depression, exaltation). Manifestly, in both emotions and moods, memory and imagination are of, at least, quite as much importance as the sensations of the present moment, 62 DISEASES OF THE NERVOUS SYSTEM and in the majority of cases of much greater significance, since they permit of the constant development of the objective content of both emotions and moods entirely freed from objective control. Feelings and emotions become associated with objects other than those originally experienced with them, and this association occurs at times in most fantastic ways. This fact of the transfer of feelings helps us to under- stand the origin and permanence of moods in both those of normal and abnormal mentality. On this basis also the affective states are designated as primary or secondary according as they are connected with the original objects or with others to which they have been transferred. It has long been held that the feelings have an important relation to the state of the body; as far back as the seventeenth century one meets the view (in Hobbes) that pleasurable feelings are associated with bodily well-being, while disagreeable feelings are both expressive of and conducive to the ill-being of the body. This relation has been subjected to much experi- mental investigation, and while the results of these researches have not been unequivocal in connection with the simpler and less intensive feelings — the heart and respiration in any case being but slightly affected — in stronger and more complex affective states the heart, bloodvessels, respiration, secre- tions, and general musculature of the body may all be involved. The effects of strong feeling and emotion upon the intellect are often marked, depending, of course, upon the intensity as well as upon the quality of the affective state. If not too strong, the association of ideas is favored and accelerated, but when violent there may be inhibition or even com- plete arrest. The positive affective states tend to increase the rapidity of associations, while those negative in direction tend to retard associations. Psychiatrists have been much influenced lately by Bleuler's monograph entitled Affectivitat. The most important anomalies of the affective life, following Ziehen's classification, include: 1. Pathological exaltation or hyperthymia. 2. Pathological sadness (depression) or dysthymia, 3. Pathological irritability. 4. Pathological apathy, general and circumscribed (hypothymia ; athymia). 5. Pathological instability of feelings (moods). 6. Pathological general increase of affective excitability. 1. Pathological Exaltation or Hyperthymia. — This is best seen as a primary phenomenon in maniacal states. All the intellectual processes are accom- panied by positive feeling tone. Even some of those which normally are asso- ciated with slight negative feeling tone appear in many to be accompanied by joyful feelings. It is not known whether the hyperthymia is really primary or is secondary to the psychic overexcitation. The experimental production of pleasurable feelings by the use of alcohol, opium, etc., supports the view that the affective state may be primary (Binswanger). Hyperthymic states may appear in the course of many psychoses, both acute and chronic. The hyperthymia is usually an episodic phenomenon. A form of secondary exaltation has been described in acute and chronic paranoid states. Here hallucinations and delusions of joyful content deter- mine the affective anomaly (Ziehen). 2. Pathological Sadness (Depression) or Dysthymia. — This pathological predominance of negative feeling tones may be primary or secondary. In DISTURBANCES OF MORE COMPLEX PSYCHIC PROCESSES 63 the primary depression the sadness may be out of all proportion to that which would normally accompany any sensations and ideas present. The depression may, indeed, be present without any apparent reason whatever. In addition to his general sadness the patient may present symptoms of anxiety. Usually this anxiety is accompanied by abnormal somatic sensa- tions (praecordial anxiety, epigastric pulsation, general unrest). Many have looked upon these somatic sensations as primary (originating peripherally), but it seems more likely that they are cortical in origin. The motor phenomena accompanying anxious states are characteristic. The rubbing of the hands, the restless movements of the legs, the rapid respiration, the palpitation of the heart, the constriction of the peripheral vessels are some of the motor and vasomotor phenomena accompanying anxious states. Such primary depressions with anxiety are usually followed by symptoms of mental retardation (thought inhibition) and the patient answers questions and performs the simplest calculations only very slowly. The general musculature of the body may be abnormally lax or abnormally rigid, as in the catatonic states. Where the anxiety movements of the body are pronounced, one speaks of anxious agitation. Sometimes movement inhibition alternates with agitation of movements. The patients are inclined to seek an explanation for their anxiety, and then arise the so-called explanation delusions. These may take the form of delusion of sin, of poverty, or of incurable disease. Primary depressions are met with as episodic states in various psychoses; in a mild form they are not infrequent in neurasthenia. The severest forms are met with in true melancholia. In the so-called secondary depressions the affective state seems to be directly dependent upon sensations and ideas with strong feeling tone. 3. Pathological Irritability. — The pathologically irritable person shows an abnormal tendency to anger and vexation. These affects appear too easily; exciting causes which in a normal person would not cause vexation call forth an affective reaction of abnormal intensity and long duration. Anger is an affect which accompanies the tendency to attack persons or objects in the surroundings. Although it is a negative affect, it differs from sadness or depression in that the feeling of self is usually elevated. The association of ideas may at first be slowed, although as the anger grows there may be a sudden and explosive acceleration of the course of ideas. At the beginning there may be a tendency to motor inhibition, but after a time, as though through summation, actions are accelerated and are often explosively violent (raving mad). During anger there is but little time for motives to come into play. The patient seems to fail to consider things at all; inhibitory ideas seem to have lost their power, or do not often come into his consciousness. His violence pays no regard to the welfare of his own person or of his surroundings. The energy of the movements may be greatly increased. The movements of anger are, however, so irregular as to be almost incoherent. This reveals itself in the speech of the angry man. He stammers and his sentences lack gram- matical sequence or coherence (anacoluthia) . It is not surprising, therefore, that after an attack of anger has passed individuals frequently show a partial amnesia of the motives leading to the passion, and even of their acts during the outbreak. (34 DISEASES OF THE NERVOUS SYSTEM 4. Pathological Apathy, General and Circumscribed (Hypothymia; Athymia). — In certain mental states feeling tones appear to be depressed or abolished. The condition is most pronounced in cases of melancholia. In many instances of neurasthenia the patients complain of loss of interest in things which nor- mally should arouse them. Their feelings for their ideals have left them. They no longer enjoy the beauties of nature, and they complain that to those nearest and dearest to them they have become indifferent. Some patients do seem much exercised over this coldness of feeling; others show no depression on this account. An appearance of general apathy may be simulated when it does not exist. The non-participation of the patient in her usual interests may be due to a conscious suppression of emotional expressions, depending upon delusions or hallucinations, or it may be the result of a motor inhibition. In contrast with this general apathy or depression of emotional excita- bility, as a whole, are the circumscribed defects in intellectual and reflected feeling tone met with especially in imbecility and dementia. In imbecility there is a faulty development of the emotional nature which may keep pace with the defect in intellectual development or may exceed it, as in moral insanity. In imbecility of milder grade, anger, envy, hate, love, gratitude, hope, and fear may be well developed, but the individual does not attain to any intellectual interests. In spite of careful education it is impossible to arouse interest in art or science. In still milder cases the ethical or altruistic feelings alone may be deficient, the egoistic feelings being abnor- mally strong. In acquired dementia, such as one sees in dementia paralytica, the loss of the higher feelings usually goes parallel with the loss of intellectual power. The changes in this disease show us very clearly the relation of conduct and behavior to our emotional life (altruistic, social, religious feelings). In alcoholic dementia, epileptic dementia, and in senility one meets with symp- toms similar to those presented by the paralytic dement. In the later stages of these acquired dementias the whole emotional life may be under- mined and a general apathy or bluntness of feeling result. 5. Pathological Instability of Feelings (Moods). — In normal individuals, there is a certain persistence or inertia to emotional states. In mental disease the moods are often much more variable. Two forms of pathological lability of moods may be distinguished, a primary and a secondary. The primary form occurs most often in imbecility and dementia, where it is associated with intellectual defects. The loosening of the associative connection char- acteristic of the intellectual defect also accounts for the instability of the irradiated feeling tones. A new sensation or idea will then sometimes in a moment lead to new irradiations of feeling tones and cause a bouleversement of mood. This is best illustrated perhaps in dementia paralytica, where a patient in tears or anger is by a suitably chosen word converted into a state of joyful exaltation. In the secondary form of instability of moods the changeability of feeling is not a primary affective disturbance, but is secondary to a pathological inconstancy and incoherence of the contents of the ideas or sensations of the patient. Where the ideas are constantly changing the moods also change. This is well illustrated in hysteria and in some forms of paranoid states. A pathological capriciousness is very characteristic of many hysterical patients. DISTURBANCES OF MORE COMPLEX PSYCHIC PROCESSES 65 6. Pathological General Increase of Affective Excitability. — In contrast with general apathy, a general increase of affective excitability seems sometimes to be met with. The individual is abnormally susceptible for all emotional impressions. This is the case in some instances of neurasthenia, but it is also occasionally met with at the beginning of severe organic psychoses. When the increase in excitability is limited to the so-called higher feelings — ethical, aesthetic, and religious — it is designated as pathological transport or ecstasy (krankhafte Ergri/enheit) . Such patients become over-enthusiastic for politi- cal, religious, or humane movements. When delusions develop upon the basis of this pathological ecstasy an eknoic state is said to exist. The so-called imperative affects are those pathological feelings which arise without cause, and which the patients themselves designate as strange or compulsory and independent of imperative ideas, delusions, or hallucinations. A patient in good humor may suddenly and without reason have a strong sympathy or a strong antipathy for some person near him, combined with a feeling that some force has artificially brought about such a tendency in him. Anomalies of Conduct (So-called Will or Volition).— Psychologists no longer recognize will as a special " faculty " of the mind. Conduct is, for them, the direct result of the total content of consciousness (sensations, percepts, memories, imaginations, feelings, emotions) of the moment. In states in which there is a general increase of motor action in mental dis- ease we speak of motor agitation; where motor action is diminished or abolished, as a whole, we speak of aboulia or motor stupor. In observing anomalies of volition one should notice not only the ordinary voluntary acts, but also alterations in speech, in expression, and in gesticula- tion. The so-called voluntary movements depend directly upon an associa- tive process leading to some goal idea, while the expressive movements (mimic and pantomimic) appear to be determined chiefly by the intensity and quality of the feelings. Disturbances of sensation, of memorial repro- duction, affective disturbances, as well as of the association of ideas proper, can all influence conduct. Of the sensory disturbances which influence volition, hallucinations and illusions are most important. A sudden hallu- cination may lead to a wholly unexpected act of violence. Wernicke has classified movements (outside of the reflex movements) into expressive, reactive, and initiative movements. By expressive movements are meant all those by which the effects and emotional states of a person are manifested. The reactive movements are those which follow direct external stimulation (answers to questions by speech or other movement; behavior on physical examination). The initiative movements are those which arise apparently spontaneously and not as a result of an immediate external stimulus, the whole conduct, behavior, action of a person in a certain situation. All movements not reflex, expressive, or reactive belong to the initiative group. Wernicke divides all psychomotor disturbances into (1) those in which there is lowered excitability or conductivity of nerve paths (akinesis) ; (2) those in which there is increased excitability or power for conduction (hyperkinesis) ; and (3) those in which there is a perverse excitability (parakinesis). It will be seen that the above classification of Wernicke is somewhat more elaborate than that of Meynert, who subdivided movements into (1) those of defence (Abwehrbewegungen) and (2) those of offence (Angriffsbewe- gungen) . VOL. vii. — 5 66 DISEASES OF THE NERVOUS SYSTEM Action may be pathological on account of the absence of ideas which are present in normal states; this absence of ideas may be due to defective devel- opment (imbecility) or to loss of memory images, following upon disease (acquired dementias). Pathological actions of this sort are designated defective acts. They often resemble the normal acts of lower animals. They may be sly and skilful, but are pathological in human beings on account of the fact that they are uninfluenced by higher and more abstract ideas. In the motor agitation of mania the pleasurable feelings lead to remarkable mimic and pantomimic motor discharges and to a logorrhoea characterized by rhymes and alliterations. In the milder forms of maniacal exaltation in which the associative con- nection of the ideas is still fairly well retained, initiative movements occur more rapidly and in greater numbers than normally, and lead to conduct which, although apparently consistent, is absurd in its motives and aims. In the severer outbreaks, stormy, contradictory, impulsive acts result from the hodge-podge of goal ideas which swim through the consciousness. The inhibiting and slowing of motor action which accompanies negative feeling tones is characteristic of melancholic states. In simple depression pantomimic movements (gesticulation) are reduced to a minimum. The voluntary muscles are generally relaxed, the arms hanging loose by the sides or the hands folded on the lap. The head sinks upon the breast, the eyes are lowered, and there is a tendency to convergence. The mandible falls and the angles of the mouth are drawn downward. The lid slits are narrowed and the eyebrows lowered except at their medial extremities. Usually the patients do not weep; indeed, they sometimes complain of an inability to weep. Often the secretion of the lacrimal glands is actually diminished, accounting for the peculiar lack of lustre of the eyes. Depressed patients have little to say, and when they speak it is in low tones. The influence of depression upon motor activity becomes changed as soon as a state of anxiety is added to the depression. At first anxiety increases the inhibition of cortical associations and tends also to slow action, but as the anxiety increases there arises the idea of flight, and the patient seeks in every way deliverance from his anxiety. He cannot rest and is impelled to walk about day and night, lamenting his state (motor agitation of anxiety). It is here that the patient so often seeks relief in suicide. Perfectly quiet for a time as a result of motor inhibition, the anxious patient may suddenly make a suicidal attempt, or he may become violent and try to injure his surroundings (incendiarism, homicide). Other patients try to still their anxiety by alcoholic excess or onanism. These attacks due to anxiety occur in paroxysms. Between the paroxysms the motor inhibition of depression is resumed. The behavior of apathetic patients varies according to the extent of the apathy (general or partial). In general apathy motor activity is reduced to a minimum. Since, normally, acts occur only when movement ideas with positive feeling tones arise in consciousness, acts cease in general apathy because most of the movement ideas which arise in consciousness are devoid of feeling tone (apathetic motor stupor). In partial apathy, where certain only of the feeling tones are lacking, it is the conduct which depends upon the presence of more complex and especially the ethical ideas which is most prone to be defective. The patient acts wholly according to his lower egoistic interests, not distinguishing between right and wrong. DISTURBANCES OF MORE COMPLEX PSYCHIC PROCESSES 67 In general apathy all the muscles of the body are lax; even the cheeks hang down. The head and limbs assume positions which depend upon gravity. The upper lids fall so as to simulate ptosis. The patients incline to lie down much of the time; in severe forms the apathy may resemble sleep. The con- dition of the pupils distinguishes the pseudo-sleep of apathy from true sleep; in the latter, when the eyelid is opened there is at first dilatation and subse- quent contraction, while in apathy the pupils are usually midway between dilatation and contraction and there is a distinct contraction at the moment light enters the eye on opening the lid. Acceleration of Motor Actions. — When motor discharges occur more rapidly then normal we speak of motor agitation, or sometimes of pathological pressure of activity. One meets with every degree of it from abnormal talkativeness with overactive facial expression to the enormous acceleration of speech known as logorrhcea. The mimic and pantomimic movements may be so much exaggerated that we have excessive grimacing and violent gesticulation. The patients are restless, they assert that they cannot sit still, and they spend their time pacing up and down the room or wandering about. Such patients may be pathologically busy, beginning a dozen and one tasks hastily and enthusiastically but quickly turning from each. In the severest forms of motor agitation when the patient becomes " raving mad," his cries may become inarticulate and his movements violent and purposeless. Such a patient may tear up his clothing or his bedding, break the furniture of his room, and attack people who come near him. Psychiatrists distinguish a primary from a secondary pressure of activity, the former corresponding to primary flight of ideas and occurring with it, the latter depending upon hallucinations or violent affects (hallucinatory agitation and affective agitation). In trying to determine whether one is dealing with a primary or secondary agitation one ascertains the presence or absence in the first place of hallucinations and delusions, or of abnormal affects, and tries to decide whether the motor agitation can be explained by these if they exist. In case they are insufficient to explain the agitation, it is probably primary. Retardation of Motor Actions. — Slowing of motor acts accompanies depressed states, which are accompanied by thought inhibition. When there is motor inhibition, together with thought inhibition and aprosexia, the condition of stupor is said to exist. One meets with mild and severe grades of motor stupor. In the milder forms movements seem difficult and are carried out more slowly than normal. The patient understands questions or commands less promptly than when he is in health. He pronounces the words of the answer more slowly, and any movements he makes are more deliberate than they should be. Mimic and pantomimic movements may be suppressed entirely. In his every-day life the patient manifests feeble will (aboulia), and is the victim of indecision. When the motor stupor reaches a high grade it may assume any one of three different forms: 1. There may be complete relaxation (resolution) of the body musculature, the patient lying for weeks or months without stirring a limb, with complete absence of resistance to passive movements, the eyes kept closed. 2. There may be a general rigidity or tension of the muscles of the body (catatonic rigidity or attonnity), the body being held stiffly in a general position of flexion (flexion type) or of extension (extension type), or in various bizarre 68 DISEASES OF THE NERVOUS SYSTEM attitudes, the eyes held tight shut, the teeth clinched. Passive movements are strongly resisted, and, as a rule, attempts at passive movement increase the general rigidity. The patients are mute and in general negativistic. Some- times, however, there is a peculiar susceptibility to motor suggestion known as command automatism. On passive movement the limbs move like wax, retaining the position in which they are put often for three or four hours (flexibilitas cerea); sometimes they repeat movements made before them (echopraxia) , or repeat words pronounced in their hearing (echolalia). 3. There may be a limitation of initiative movements to a few acts repeated continuously for hours, days, or months at a time (stereotyped movements), the patient rocking to and fro or from side to side, or continuously rotating the head or the trunk. One tries to make out in each case whether the motor inhibition is primary (true stupor) or secondary (pseudo-stupor) . Primary motor stupor corresponds to primary depression of thought activity, being part of the general slowing of associative processes (e. g., in melancholia). Usually it takes the type of relaxation of the muscles or of simple catatonic rigidity. In secondary motor inhibition the pseudo-stupor may depend upon definite hallucinations, delusions, or affects. Incoherence of Motor Actions. — When there is incoherence of the association of ideas the motor acts also become incoherent (motor incoherence); the patient is in a state of confusion. In its mild form it betrays itself in a pecu- liar lack of plan in the more complex acts of the patient. On going for a walk he may wander hither and thither without aim and out of accord with the purpose which he at first had in mind. Such a patient will busy himself first with one thing and then with another in a most unsystematic way. In the worst forms of confusion the acts become nonsensical and stand in no correct relation to the ideas preceding them (parapraxia and apraxia).2 The patient does not know how to use simple objects. He cannot light a match, cannot open a knife, may try to eat milk with a fork, and may bite his own finger instead of a morsel of food held in his hand. The confusion may extend to speech and writing, the patient designating objects falsely (paraphasia, paragraphia) . The movements of the body may become incoordinated, resembling ataxia or chorea. Even the mimic movements may no longer correspond to the underlying affect. The patient's grimaces are out of accord with his feelings ; his laughing and crying stand in no ascertainable relation to the content and feeling tone of his ideas (paramimia). Motor incoherence is sometimes combined with motor agitation, the mixed state being designated incoherent agitation and the excessive incoherent movements described as jactitations (chorea magna of the older writers). When this is accompanied by fever the condition has been called delirium acutum. The motor incoherence is called primary when it cannot be attributed to other psychopathic states (e. g., in the incoherent form of paranoia). It is called secondary when it is due to hallucinations, delusions, flight of ideas, affective disturbances, or imbecility. Anomalies in the Intensity and Duration of Acts (Change of Acts). — In health initiative movements undergo changes corresponding to the changes which 1 For the differential diagnosis of the different forms of stupor the reader is referred to Ziehen's Psychiatric, second edition, Leipzig, 1902, p. 156. 7 Wilson (S. A. 1C), Studies in Apraxia, Brain, 1908. DISTURBANCES OF MORE COMPLEX PSYCH 1C PROCESSES 69 take place in the sensations and ideas in consciousness. When special motives are present certain movements may become dominant. In mental disease, however, dominant movements or acts may appear without adequate moti- vation (hyperdynamic acts). These hyperdynamic acts may be primary (not due to other psychopathic symptoms). A good example is seen in the so- called tics. Most hyperdynamic acts are, however, secondary to delusions, hallucinations, or anxious states. The monotonous recurrence of a certain act or attitude (motor stereotypy) is probably due to a more or less permanent psychomotor hyperdynamy. Among the interesting stereotyped movements frequently met with are the snout-like movements of the lips (snout cramp) and constant blepharospasm. Sometimes the stereotypy manifests itself in certain bizarre movements, the so-called mannerisms. Many patients have a stereotyped scanning speech or vary the pitch of their voice in monotonous repetition. Sometimes single syllables or sounds are intercalated in the speech, a habit usually regarded as affectation, but spoken of by psychiatrists as stereotyped embolophrasia. When a motor innervation has been completed and there is a tendency on the part of a patient to repeat it afterward, even when other movements are required of him, the condition is designated motor per generation. A common example is the repeated showing of the tongue, after one has asked to see it, even when the patient is subsequently requested to show his teeth, to beckon with his finger, or to close his eyes. This motor perseveration, being due to a request or stimulus from the outside, is to be distinguished from the stereotypy which has its origin within. Temporary motor hyperdynamy reveals itself in the so-called impulsive acts due to a sudden affect, delusion, imperative idea, or hallucination. Anomalies of Conduct Due to Delusions and Imperative Ideas or to Imbecility and Dementia. — A patient who has delusions or imperative ideas will often reveal the character of the delusions or the ideas in his conduct. The whole facies and the attitude of the patient with delusions of grandeur are char- acteristic and are in marked contrast with the appearance and behavior of the patient suffering from delusions of self-depreciation. When delusions of persecution exist, the patient is ever on the defence (bolting of doors, sudden flights to escape enemies). Sometimes the persecute becomes the per- secuteur; then, instead of defensive movements, he may assume the attitude of attack. Such patients are usually dangerous in the community (paranoia) . Impulsive acts are sometimes due to the "pathological notions" described in an earlier paragraph. The so-called imperative acts are the result of the imperative ideas also previously described. Here the patient recognizes the absurdity of his act, but performs it all the same. One should distinguish carefully the imperative idea which is accompanied by the impulse to motor action and that not associated with such motor impulse. In the former case the imperative act frequently results, in the latter it does not. In mysophobia the continuous washing of the hands for hours at a time is an illustration of an imperative act. A child's imitation of its parents may be regarded at a certain stage of development as a normal echokinesis, but later on direct imitation of movements observed ceases to Ge desirable, and the tendency is normally suppressed. The abnormal patient may, however, imitate movements which he sees or sounds which he hears, as in the echolalia above mentioned. The influence of defective judgment upon the conduct becomes obvious 70 DISEASES OF THE NERVOUS SYSTEM in the study of imbecility and the various forms of dementia. The acts of defectives reveal the absence of those complex ideas which normally deter- mine the play of our motives. There is an absence of due consideration before action. The so-called criminal acts doubtless belong here. Disturbances Of Motility Proper. — In the preceding sections motor dis- turbances of psychic origin have been referred to. We have now to consider the disturbances of motility less directly psychic or entirely infrapsychic in their origin, disturbances due to alterations in function of the motor path- ways from the cerebral cortex to the muscles, or to alterations in the cortex itself or in the muscles themselves. Atrophy and Hypertrophy of Muscles. — The state of nutrition of the muscles yields important clues to the nature of many nervous diseases. Muscular atrophy may or may not be associated with paralysis of muscles. Simple atrophy of the muscles should be distinguished from .so-called degenerative atrophy. In the former there is only a quantitative diminution in size; in the latter there is in addition an actual degeneration of the muscle substance. Degenerative atrophy occurs in lesions of the lower motor neurones (anterior horn cells, motor nuclei, or cerebral nerves, peripheral motor nerves). Simple atrophy may be due to disease of the muscles themselves or to lesions of the motor conduction paths situated above the lower motor neurones (e. g., pyramidal tract lesions). It may be due simply to disuse (atrophy of inac- tivity). In true degenerative atrophy the so-called reaction of degeneration is found on electrical examination. Where the degenerative atrophy is due to lesion of the anterior horns or of the motor nuclei of the cerebral nerves, fibrillary twitching is commonly present. It is rare to find it in the lesions of the peripheral motor nerves. The muscles may be the seat of a true hypertrophy in athletes. There is localized hypertrophy of muscles which are subject to cramp-like processes which continue a long time. A condition resembling hypertrophy of the muscles, but which in reality is due to increase of connective tissue and fat, the muscle substance itself being in reality diminished in amount, is seen in certain types of muscular dystrophy (so-called pseudo-hypertrophy). Muscular Tone, Atony, Hypotony, Hypertony, Contractures. — The condition of tone (tonus) presented by the voluntary muscles is of importance for diagnosis. When the resistance to passive movement is abnormally small, we speak of hypotony or atony or resolution of the voluntary muscles. When there is an abnormally strong resistance to passive movement, we speak of rigidity or hypertony of the muscles. It is conspicuously present in the various spastic paralyses, in many motor spasms, in catatonia, etc. When along with hypertony a muscle remains permanently contracted, we speak of spastic contracture. When certain muscles are paralyzed and on subsequent voluntary innervation only the antagonists contract, there comes a time when relaxation of these antagonists no longer results in a normal position of the limbs. Such a permanent shortening of the antagonists is sometimes spoken of as paralytic contracture. In contrast with these neuro- pathic contractures (spastic and paralytic) there occur also myopathic con- tractures due to inflammation of the muscles and tendons, contractures from shortening of fascia as a result of scars, contractures of reflex origin, and hysterical contractures. Paralyses. — Inability to bring the muscles to contraction is known as paralysis. Paralyses may be classified in different ways: (a) According to DISTURBANCES OF MOTILITY 71 the state of nutrition of the muscles; (6) according to the state of ton us of the paralyzed muscles ; (c) according to the distribution of the paralysis. As regards the classification according to the state of nutrition of the muscles, paralyses may be divided into (1) atrophic, and (2) non-atrophic paralyses. By atrophic paralysis is meant a special form not due simply to disuse and accompanied by rapid reaction of degeneration. It indicates a lesion of the lower motor neurones, either in their nuclei of origin or in the peripheral nerves. By non-atrophic paralysis is meant the form in which the paralyzed muscles undergo but little shrinking in volume; on electrical examination no reaction of degeneration can be made out. According to the state of tonus of the paralyzed muscles, paralysis may be divided into (1) flaccid paralyses, and (2) spastic paralyses. Flaccid par- alyses are usually associated with loss of the deep reflexes, while spastic paralyses are usually associated with exaggeration of the deep reflexes. The flaccid paralyses are due, as a rule (although not always), to lesions of the lower motor neurones. The spastic paralyses are due nearly always to lesions of the upper motor neurones. As regards the distribution of the muscles paralyzed, paralyses are divisible into: (1) Neural paralyses; (2) plexus paralyses ; (3) radicular paralyses ; (4) paralyses of one extremity or of the face (monoplegias) ; (5) paralyses of half the body (hemiplegias) ; (6) paralysis of both lower or both upper extremities (paraplegias). In the neural paralyses a single muscle or the muscle innervated by a single nerve may be involved (e. g., Bell's palsy). In the plexus paralyses the whole or a part of the muscles supplied by the brachial or lumbosacral plexuses may be involved. The paralyzed muscles in radicular paralyses correspond to the motor innervation from single nerve roots. The monoplegias may be due to lesions of peripheral nerves or of the central nervous system. The face may be alone affected (monoplegia facialis); if it be the arm alone we speak of monoplegia brachialis; if the leg alone, of monoplegia cruralis. When the musculature of one-half of the body is paralyzed the condition is known as hemiplegia. If the muscles are only weakened, the term hemiparesis is employed. A hemiplegia may be organic or functional; it may be flaccid at first, but is usually spastic later; it may or may not be accompanied by sensory disturbances (hemiansesthesia; hemianopsia). It may be cortical, capsular, peduncular, pontile, or medullary in origin. A hemiplegia may be associated with paralysis of the muscles supplied by the opposite oculomotor nerves (hemiplegia alternans superior, or Weber-Gubler type) ; or the face may be paralyzed on one side and the arm and leg on the other (hemiplegia alternans inferior, or Millard-Gubler type). The term paraplegia is usually restricted to paralysis of both lower limbs, with more or less involvement of the trunk muscles. The paraplegia may or may not be associated with sensory changes; it may be organic or functional, flaccid or spastic. The flaccid paraplegias may be due to disease of the spinal cord or the peripheral nerves, while the spastic paraplegia is due to lesions of the upper motor neurones, either in the spinal cord or at a higher level. The Brown-Sequard syndrome is sometimes spoken of as a hemiparaplegia. When all four extremities are paralyzed, owing to a lesion in the cervical cord, the paralysis is spoken of as a cervical paraplegia. Motor Irritation. — The various forms met with include: (1) Tremor. (2) Fibrillary twitchings. (3) Athetoid and choreiform movements. (4) Clonic and tonic spasms. 72 DISEASES OF THE NERVOUS SYSTEM By tremor is meant rhythmical, involuntary, frequent oscillatory move- ments of slight extent. The tremor may be fine or coarse; thus, that of Graves' disease is very fine and the rate varies from 8 to 10 oscillations per second ; in paralysis agitans, on the other hand, the tremor is coarser and the oscillations less frequent (2 to 4 per second). A tremor which appears only when voluntary movements are undertaken is known as an intention tremor. It is met with especially in multiple sclerosis. Closely related to it is nystagmus. By fibrillary twitchings are meant the contractions of single fiber bundles of any given muscle, the contractions being insufficient to lead to any loco- motor result. Fibrillary twitching is a totally different thing from tremor. It is met with especially in disease processes in which the muscle is degener- ating, owing to lesion of the cell bodies of the lower motor neurones. By athetoid movements are meant certain slow, involuntary movements of extension, flexion, adduction, and abduction, each individual part moving by itself independent of the others, so that the various parts may at any given moment occupy very different relative positions in space. The movements may be unilateral (hemiathetosis) or bilateral. Choreiform movements include the involuntary, quickly changing move- ments, made without plan or purpose, met with in various diseased condi- tions. They are not confined to the hands and feet, but may involve any of the voluntary muscles of the body. This fact, together with the greater quick- ness of the movements, distinguishes them from athetoid movements. The movements are best studied in chorea minor (St. Vitus' dance; Sydenham's chorea). A unilateral chorea is not infrequent after hemiplegia (post- hemiplegic hemichorea). In hysteria a very coarse form of chorea known as chorea major is sometimes met with. It is frequently associated with clownism; in the same disease a form of chorea occurs in which there are quick, lightning-like contractions in single muscles similar to those which follow upon electrical stimulation (chorea electrica). Involuntary movements of certain muscles which accompany voluntary movements of other muscles are known as associated movements (muscle synergies). One sees such movements frequently in the paralyzed limb of hemiplegics on strong voluntary innervation of the healthy limb. The tibial phenomenon of Striimpell may be regarded as an instance of a spinal associated movement due to injury of the pyramidal tracts. When it is present flexion of the lower extremity at the hip-joint and knee-joint calls forth a dorsal flexion of the foot and elevation of the medial margin of the foot, despite the patient's effort to suppress these movements. Spasms and convulsive movements are among the commonest instances of motor irritation. By clonic spasms are meant involuntary quick jerkings of the muscle which follow one another rapidly without interruption. If the distribution includes a large number of muscles at any one time, we speak of clonic convulsions. In tonic spasm the individual muscular contractions last a long time. When a single muscle is involved with severe pain the condition is known as cramp. When muscle groups are affected together, or the whole body is involved, we speak of tetanus and tetanic contractions. Convulsive seizures or convulsions occur in epilepsy, hysteria, tetanus, and eclampsia. In the ordinary epileptic attack the convulsion consists at first of a tonic spasm of the whole body musculature, followed after a short time bv clonic spasms. In cortical irritation a peculiar type of epileptiform convul- DISTURBANCES OF MOTILITY 73 sion known as the Jacksonian attack occurs. The muscular contractions begin in single muscle groups and radiate into other motor domains (so-called "march" of the convulsion). In hysteria the convulsive movements may resemble those of epilepsy, although they are usually much more violent and the movements are more varied, even leading to remarkable attitudes (arching of the back, etc.). In tetanus there is tonic spasm of the muscles affected. This often leads to lockjaw (trismus), to spasm of the face muscles, giving rise to a laughing expression (risus sardonicus), to arching of the spine with retraction of the neck (opisthotonos) , and sometimes to tonic spasm of the abdominal and respiratory muscles. In tetany we meet with intermittent tonic spasms of bilaterally symmetrical groups of muscles, associated with painful sensations and paraesthesias. The attitude of the hands and forearms is especially characteristic (" obstetrical hand"), but muscles in various parts of the body may be attacked. Even when the spasm has passed off in the arms it may be reproduced by applying pressure to the arm above the elbow with a blood pressure apparatus ( Trous- seau's phenomenon). The mechanical excitability of the muscles of the face is greatly increased. Mere stroking of the cheek or tapping upon the branches of the facial nerves (pes anserina) with a percussion hammer calls forth quick muscular contractions in the face (Chvostek's phenomenon). The sensory nerves may also be hypersensitive, and tapping at Valleix's points then calls forth abnormally intense sensations (Hoffmann's symptom). On electrical stimulation the motor nerves are found to be hyperexci table in tetany (Erb's phenomenon). In Thomsen's disease (myotonia congenitd) there exists a so-called intention rigidity of the muscles. On voluntary contraction of any group of muscles there results an abnormally strong contraction of long duration which leads to motor inhibition. Gradually the muscles relax again. In psychasthenia and in certain other psychoneurotic states sudden contractions of the muscles known as tics are met with. In the so-called maladie des tics of Gilles de la Tourette the musculature of the whole body may be involved, and the condition is associated with mental deterio- ration. Disturbances of Coordination (Ataxia). — The mechanism by which muscles act together for purposeful effects is known as coordination. Almost every voluntary movement requires the simultaneous and successive activity of several muscles (synergists) ; some of the muscles are contracting (ago- nists); others are relaxing (antagonists). The grouping of contractions, their succession, and the force of each have to be carefully regulated in order that the movements shall be harmonious and purposeful. Disturbance of this mechanism leads to the anomaly of movement known as ataxia. The presence of ataxia is not necessarily combined with weakness of the muscles. It is, however, frequently associated with loss of deep sensibility and with hypotony of the muscles. It seems certain that ataxias are due more to interference with the centripetal or sensory paths than to interference with motor conduction paths. In the so-called cerebellar ataxia there is a disturbance of equilibrium, manifested especially on standing and walking. The patient stands with his feet wide apart and sways on walking from side to side like a drunken man . His tendency on walking is to let his legs run ahead of his body (asynergie 74 DISEASES OF THE NERVOUS SYSTEM cerebelleuse of Babinski). In trying to rise from the recumbent position, the patient, instead of lifting his trunk, is likely to lift his legs in the air. In cerebellar disease, the patient lying on his back with the lower extremi- ties in the air, the thighs flexed and the legs abducted, can maintain some- times a fixation of position beyond that possible for a normal man; the lower extremities behave as though cataleptic (Babinski). On the other hand, the capacity (diadokokinesis) to carry on quickly a series of antagonistic move- ments, such as rapidly alternating pronation and supination, may be les- sened (so-called adiadokokinesis) . Electrical Condition of the Muscles and Nerves.— Much information of value concerning the state of the muscles and motor nerves can be arrived at by careful electrical examination. One determines the excitability and conductibility of the motor nerves and the direct excitability of the muscles. Increased excitability to electrical stimulation is not very common. It is occasionally met with in a beginning neuritis, in tetany, in beginning demen- tia paralytica, etc. A lessened excitability is met with in all old paralyses due to lesions of the upper motor neurones and also in the myopathic form of muscular atrophy. The most important electrical reaction for diagnostic purposes is the so- called reaction of degeneration (De R). When it is complete, changes in the electrical excitability, both in the nerves and muscles, are demonstrable. The excitability of the nerves for both faradic and galvanic current grows less and less until finally it disappears. The excitability of the muscle decreases for the faradic current pari passu with that of the nerves until it also is finally abolished, but the excitability to the galvanic current undergoes a remarkable change. Instead of a quick, lightning-like contraction the reaction to the galvanic current becomes slow, worm-like, and long drawn out, and the current, when applied directly to the muscle, shows an increased excitability of the latter, very feeble currents calling forth contractions. In addition there is a reversal of the normal law of contraction; normally, the cathodal closure contraction can be produced with the feebler current, whereas in reaction of degeneration anodal closure contraction is more easily produced than cathodal closure contraction, and the cathodal opening contraction approaches in ease of producibility that of the anodal opening contraction. In curable cases the movements return before the electrical excitability becomes normal. When the reaction of degeneration is present it is proof positive of a lesion of the lower motor neurones, although it may affect either the cell bodies of the neurones, the peripheral motor nerves, or the nerve endings in the muscles; thus, a reaction of degeneration is common in anterior poliomyelitis, in progressive muscular atrophy, in syringomyelia involving the anterior horns, in the various forms of neuritis, and in diseases affecting the bulbar motor nuclei. There is no reaction of degeneration in lesions of the brain and cord which do not involve the lower motor neurones, nor is it present in the so-called pure primary muscular atrophies (dystrophies). In myotonia congenita the so-called myotonic reaction of Erb is obtained, which is peculiar in this, that the muscular contraction lasts for a long time on direct faradic and galvanic stimulation after the current is again opened, and, besides, peculiar wave-like contractions can be produced if one stimulates the muscle near its insertion, placing the other electrode near the origin of the muscle. DISTURBANCES OF MOTILITY 75 In myasthenia gravis the so-called myasthenic reaction of Jolly can usually be obtained. It is a sign of exhaustion quite in accord with the other phenom- ena of the disease. A tetanizing faradic current when first applied shows the presence of normal excitability, but gradually the response diminishes and in a short time no response can be elicited. Anomalies Of Gait. — The limits of normal variation in gait are wide and should be borne in mind in studying pathological cases. There are several tolerably characteristic gaits to be distinguished. Among the more important are the wobbly gait, the paretic gait, the spastic-paretic gait, the spinal ataxic gait, the cerebellar ataxic gait, the gait of tremor, the hemi- plegic gait, and the gait of intermittent claudication. The wobbly gait is often due to paralysis or atrophy of the M. gluteus medius et minimus. It is also seen in congenital dislocation of the hip-joint. The paretic gait assumes two types, the simple paretic gait and the partial paretic gait. In the simple paretic gait, due to muscular weakness only, the movements of walking are slowed and the steps are shortened. Frequently there is an exaggerated flexion at the knee-joints. In severer cases the patient has to walk with crutches. In the partial paretic gait certain only of the muscles are weak. The most common form is that due to paralysis of the peroneal muscles on both sides. There is toe-drop, leading to lengthening of the leg; in order to compensate for this the lower extremity must be over- flexed at the hip and knee. This gait resembles to a certain extent the movements of a horse; it was described by Charcot under the name of steppage. In the spastic-paretic gait the weak muscles are hypertonic and the stiffness slows the movements and diminishes the excursions. The lower extremity moves more or less, as a whole. The toes cling to the ground ; the difficulty in flexing the knee and hip is partly overcome by elevation of the pelvis on the side of the swinging leg. Often there is adductor spasm in the thighs, so that the knees rub against one another, and there is a tendency of the legs to cross on walking. In hemiplegia with spasticity the rigid limb swings lateralward, making a movement of circumduction, distinguishing it from the gait of hysterical hemiplegia, where the paralyzed leg is "dragged" forward. In cerebral softening and especially in pseudo-bulbar paralysis the steps are often very short, the foot being lifted from the ground only with difficulty. This gait is spoken of as demarche a petits pas. The spinal ataxic gait is very characteristic and is easily recognized. The excursions of the movements are all exaggerated, the hip is overflexed and rotated lateralward, the toes are lifted and the whole leg suddenly thrown forward, the foot being brought to the ground with a stamping sound. The feet are kept wide apart and the patient watches his movements closely, being almost sure to fall if he looks away. Two kinds of cerebellar ataxic gait are described, one due to disturbance of equilibrium and often associated with vertigo, the other depending upon a movement ataxia. In the former, the gait resembles that of a drunken man, the patient swaying from side to side in a very irregular manner. In the latter, the patient walks with his feet far apart, stamping on the ground, but without the wide excursions of the spinal ataxic gait. The character of the gait in tremor depends upon the cause of the tremor. Gaits more or less characteristic are met with in multiple sclerosis, in hysteria, and in paralysis agitans. In the latter, in addition to the stooped attitude fft DISEASES OF THE NERVOUS SYSTEM of the patient, we meet with the phenomena of propulsion and retropulsion; the patient walking forward or backward has difficulty in stopping himself. In hysteria inability to stand and walk is sometimes a prominent symptom (astasia-abasia) . In intermittent claudication the patient after walking a short time has pain, fatigue, and numbness in the leg; these symptoms increase rapidly in severity until further movement becomes impossible. On resting for a short time the patient can again walk for a little while, but only to meet with a recurrence of the symptoms (arteriosclerosis of the arteries of the lower extremities). Anomalies Of Speech and Writing.1 — Disturbance in the articulation of the speech sounds is known as dysarthria. In its highest grade speech sounds can no longer be emitted (anarthria). Dysarthria may depend upon weakness of the muscles of the lips, of the tongue, of the velum palatinum, or of the larynx. The speech has a nasal twang in cleft palate and in paralysis of the velum palatinum. It is often heard in patients with adenoids. In bulbar paralysis it is the lingual letters (s, 1, d, t, n) which are difficult at first; later the labials (p, b, m, f, w, o, u) are affected, and finally the gutterals (g, k, ch, r) become indistinct. When the speech is especially slowed (convalescence from acute disease, psycho-motor retardation) the condition is known as bradylalia. When the individual syllables are separated by abnormally long pauses, the condition known as scanning speech is said to exist. It is especially characteristic of multiple sclerosis, and can be demonstrated by asking the patient to pro- nounce such words as Constantinople, circumstantiality, etc. In stuttering there are spasmodic contractions of some of the speech mus- cles, interfering with production of the speech sounds. It is to be distinguished from stammering (dysarthria literalis) by the fact that in the latter spastic muscle contractions are absent. In stuttering the trouble with speech often disappears when the words are sung. Under observation stuttering is exaggerated, while stammering is usually somewhat lessened. There is a form of syllable stumbling which is met with especially in dementia paralytica, and is of great importance for diagnosis. In studying aphasic disturbances it must be kept in mind that speech con- sists of two great groups of functions, the perceptive (understanding of speech) and the expressive (act of speech). The anomalies on the perceptive side are included under the general term of amnesic or sensory aphasia (Wernicke). The memory for words can be disturbed in various ways; thus, the memory of names may be wholly or partially lost. The disturbance in which a patient hears spoken words but does not recognize their meaning is known as word deafness. When the patient whose speech muscles are not paralyzed has certain words and syllables in his consciousness but is unable to give expression to them in speech, he is said to suffer from motor aphasia. Such patients also are unable to speak words pronounced before them. They are never entirely dumb, being always able to give expression to a few words or parts of words ; indeed, there is every gradation from syllable stumbling to almost complete dumbness. 1 For the literature of the subject and for excellent accounts the reader is referred to von Monakow (C.). Gehirnpathologie, second edition; Dejerine (J.), Semiologie du systeme nerveux in Bouchard's Traite de pathologic generate, Paris, 1901, vol. vj and Moutier (F.), L'Aphasie de Broca, Paris, 1908. ANOMALIES OF SPEECH AND WRITING 77 Similar to aphasia are the disturbances known as agraphia and apraxia. In agraphia, although there is no actual paralysis of the muscles of the upper extremity, the patient is unable to write down words which he hears or sees or remembers. Usually agraphia is combined with aphasia, but in pure agraphia it exists by itself without aphasia. In apraxia (or dyspraxia) the patient is unable to carry out from memory certain complicated movements of his limb muscles. Apraxia seems to be due most often to lesions of the left hemisphere or of the corpus callosum. The incapacity to understand written or printed matter is known as alexia. When all the components of speech (perceptive and expressive) are inter- fered with, the condition is known as total aphasia. When the speech anomaly is chiefly on the expressive side, we designate it a motor aphasia. In the most common form of motor aphasia, that known as Broca's type, speech is almost abolished and the patient is unable to pronounce words spoken before him. He cannot read aloud, he has difficulty in spontaneous writing, in writing to dictation, and in copying. He may, however, understand words which he hears and sees. In cases of this type, in which the agraphia is much more pronounced than the speech disturbance, the special term of cheirokinesthetic agraphia has been applied. In so-called pure motor aphasia (subcortical motor aphasia or aphemia; pure word dumbness) there is almost complete inability for spontaneous speech, for pronouncing words spoken before the patient, and for reading aloud, but there is no disturbance of writing and the understanding of speech and of writing is normal. In sensory aphasia, as has been said above, it is the perceptive side of speech which is interfered with. Here, again, we dis- tinguish ordinary sensory aphasia (Wernicke's type) from pure word deafness. In ordinary sensory aphasia of Wernicke's type (cortical sensory aphasia) the patient is unable to understand what he hears and reads. His store- house of spoken words is somewhat diminished and his speech is paraphasic in that instead of using the words which he intends to employ he gives expression to others which have a similar sound. He is unable to pronounce words spoken before him, or if able to do so does not understand their meaning. The emphasis he puts upon spoken words is faulty. On spontaneous writing and on writing to dictation he manifests a verbal agraphia or mixes up the letters in words (paragraphia) . He copies only with difficulty. In so-called pure word deafness (subcortical sensory aphasia) internal speech may be normal, there is some deafness, and the patient is totally unable to understand words spoken to him, nor can he speak words pronounced before him. He may, however, be able to express himself quite well in writing and to understand what he reads. At the beginning of the sensory aphasias, especially in tumors or after brain injuries, patients sometimes pass through a transitory state in which motor speech is undisturbed, but there is difficulty in finding the names for objects and persons (concrete substantives). Such patients understand spoken and written words perfectly well, but on spontaneous writing they have the same difficulty as on speaking, although writing to dictation and copying may be quite normal. This particular condition is sometimes spoken of as word amnesia or anomia. Two kinds of pure word blindness (subcortical alexia of Wernicke) have been described, one without agraphia, the other with agraphia. In pure 78 DISEASES OF THE NERVOUS SYSTEM word blindness without agraphia spontaneous speech and the understanding for spoken words are normal, but single letters and syllables cannot be read. The patients may write, but fail to understand the words that they have written themselves. They can write to dictation, but cannot copy. The con- dition is usually associated with hemianopsia dextra. In pure word blindness with agraphia spontaneous speech and the under- standing of spoken speech are normal, but there is complete alexia com- bined with agraphia and paragraphia, these symptoms being optic in their origin. The patient cannot write to dictation nor can he copy the writing of others. Anomalies Of the Reflexes. — A study of the disturbances of reflex action is of great importance in neurological and psychiatric diagnosis. Three main groups of reflexes should be examined: (1) The pupillary reflexes. (2) The deep reflexes (tendon and peri osteal reflexes). (3) The superficial reflexes (cutaneous and mucosal reflexes). Pupillary Reflexes. — These include (1) the light reflex, and (2) the accom- modation and convergence reaction. In testing the light reflex one must avoid calling forth movements due to accommodation or convergence. Each eye should be tested for itself, and one should also see whether or not the consensual reflex is present, remembering that on unilateral illumination there should be a pupillary contraction in both eyes. In testing the reaction on convergence one asks the patient to look first at the ceiling and then quickly at the end of the nose. When the eyes converge for near vision there is also a contraction of the pupil due to accommodation. But even when the medial recti are paralyzed and convergence is no longer possible, there may be an accommodative pupillary contraction. If the light reflex is abolished or diminished the condition is known as reflex pupillary rigidity. This may be due to partial or complete blindness (amau- rosis or amblyopia) or to paralysis of the M. sphincter iridis; in other words, it may depend upon the centripetal fibers of the reflex arc (nervus opticus) or upon the centrifugal fibers of that arc (nervus oculomotorius). When the pupils do not react to light but do react well on accommodation and convergence, we speak of the Argyll-Robertson pupil. Its presence is of very great significance in the diagnosis, especially of tabes and of dementia paralytica. The condition is usually bilateral, but may in early stages be unilateral. When the pupils react neither to light nor accommodation (abso- lute pupillary rigidity), there is complete ophthalmoplegia interna. This condition is not uncommon in cerebral syphilis, and may be met with also in brain tumor, tabes, or dementia paralytica. The size of the pupils varies a good deal in health with moderate illumi- nation. Abnormal contraction of the pupils (myosis) occurs in opium poison- ing and in various conditions which irritate the oculomotor nerve or paralyze the sympathetic nerve. It should be borne in mind that myosis occurs physiologically in old people and in sleep. Abnormally large pupils (mydri- asis) are seen in atropine and cocaine poisoning. The condition may also be due to oculomotor paralysis, to atrophy of the optic nerve, or to irritation of the cervical sympathetic. Inequality in the size of the pupils (anisocona) may be due to unequal illumination or to differences in the refractive media of the two eyes, but most often it indicates unilateral nervous disease of the optic, oculomotor, or ANOMALIES OF THE REFLEXES 79 sympathetic nerves. It is not infrequently present in dementia paralytica and in tabes. Deep Reflexes. — Of these, by far the most important are the knee-jerk, the heel-jerk, and the periosteal reflex. The knee-jerk (patellar tendon reflex, knee kick) is the contraction of the M. quadriceps femoris which follows tapping upon the ligamentum patellae. Sometimes the so-called reinforcement of Jendrassik is necessary; the patient clasps his hands and is told to pull at the moment one taps the patellar tendon. As a rule, it is more satisfactory to make the examination in the recumbent position. Achilles-jerk or Foot-jerk. — The patient is placed on his knees in a chair, the feet hanging loosely over the end of the chair. One then taps upon the Achilles tendon with a percussion hammer. The reflex is not always present, even in healthy people, although generally so. If the Achilles jerk be exag- gerated the percussion stroke may give rise to clonic contractions or an actual foot clonus instead of to a single contraction. Periosteal Radial Reflex — On tapping the lower end of the radius one can see a contraction of the M. brachioradialis at the bend of the elbow, leading to flexion and slight pronation of the forearm and hand. The other deep reflexes which may be tested are: (1) Tibial reflex (strik- ing anterior surface of tibia to get contraction of M. quadriceps femoris); (2) the biceps reflex (tapping the biceps tendon at the bend of the elbow); (3) the triceps reflex (holding arm at a right angle and tapping on the triceps tendon); (4) the jaw-jerk (laying finger above chin with the mouth closed and giving slight tap with percussion hammer to get contraction of the masseters). The deep reflexes may be increased or diminished. An increase may be due to irritation of the sensory limb of the arc (neuritis, meningitis), to stimu- lation of the anterior horn cells (strychnine poisoning), or to diminution of inhibitory influences acting from above upon the reflex arc (neurasthenic states, lesions of the pyramidal tract). The deep reflexes may be diminished or abolished through injury to the sensory or motor nerves or injury to the portion of the arc within the central nervous system. Cutaneous Reflexes. — The three principal ones to be considered are: (1) The plantar reflex; (2) the cremaster reflex; (3) the abdominal reflex. The plantar reflex is elicited by applying a stimulus to the sole of the foot. Under normal conditions it leads to an involuntary contraction of certain muscles of the lower extremity, the so-called "tickle response" being a kind of movement away from the irritating object. Most important, however, is the behavior of the toes, and especially of the great toe. Under normal condi- tions plantar stimulation is followed by plantar flexion of the toes.1 On the contrary, when the pyramidal tract is injured, instead of plantar flexion there is dorsal flexion, especially of the great toe, and the movement of the toe occurs less rapidly than under normal conditions (Babinski's phe- nomenon). In children during the first few months of life, plantar stimulation causes dorsal flexion of the great toe, but after the first few months of life the normal reflex is one of plantar flexion. When the pyramidal tract is diseased the dorsal flexion of the great toe is often accompanied by 1 Babinski, Sur le reflexe cutane plantaire, Comptes rendus de la Soc. de Biol., 1897. gO DISEASES OF THE NERVOUS SYSTEM spreading of the other toes, and especially by abduction of the little toe. This has been called by Babinski the fan sign (signe de I'eventail). Similar in its meaning to the Babinski phenomenon is the response obtained by rubbing the medial surface of the tibia downward with the pulp of the thumb or with the handle of a percussion hammer. Normally, as the malleo- lus is approached, this causes plantar flexion of the toes, but in spastic states there results, as a rule, dorsal flexion of the foot and especially of the great toe (Oppenheim's sign). Still another sign of similar import may be mentioned. If one taps the lateral part of the proximal half of the back of the foot, corresponding to the base or middle of the third and fourth metacarpal bones, the cuboid bone, and the second cuneiform bone, dorsal flexion of the toes occurs under normal conditions, while in spastic states we meet, instead, with a plantar flexion of the toes, sometimes with spreading of the toes (Mendel's sign). Cremaster Reflex. — This is elicited by stroking the medial surface of the thigh in the adductor region or by pinching the skin in this location. The normal response consists in a contraction of the cremaster muscle, with ele- vation of the testicle. This reflex is not to be confused with the scrotal reflex, which consists of a contraction of the tunica dartos with wrinkling of the skin of the scrotum on stimulation of the skin in this neighborhood. Abdominal Reflexes. — One strokes the skin of the abdomen with the end of the finger or with the blunt point of some instrument, and notices the con- traction of the abdominal muscles which follows. It may be elicited either in the supra-umbilical or in the infra-umbilical region on each side (epigas- tric and hypogastric reflexes). A unilateral absence of the reflex is of most importance. Other Cutaneous and Mucosal Reflexes. — Among the other reflexes may be mentioned the palmar reflex, scapular reflex, and the uvular reflex. Especial mention perhaps should be made of the lid reflex (closure of the lids when an object is brought suddenly near one eye) and the conjunctival and corneal reflexes (closure of lid on stimulation of the conjunctiva or cornea). The reflexes set free by stimulation of the skin and mucous membranes have an entirely different significance from the deep reflexes. The cuta- neous reflexes may be absent when the peripheral nerves are diseased; indeed, whenever the reflex arc is interrupted. One of the most interesting facts connected with the cutaneous reflexes is that they are especially disturbed in unilateral cerebral disease. Aside from the Babinski phenomenon, a hemiplegia usually leads to loss of the abdominal and cremaster reflexes on the paralyzed side, perhaps owing to an increase of the influences which inhibit the activity of the reflex arc, although this explanation is not universally accepted. Anomalies of the Vasomotor, Secretory, and Trophic Functions.— The vasomotor functions of the nervous system are very complex, and dis- turbances in different parts can lead to vasoconstriction on the one hand, or to vasodilatation on the other. For a full discussion of these vasomotor phenomena the reader is referred to the recent lecture by Porter,1 the article by Eulenburg-Landois, and to the excellent treatise of Cassirer.2 Here belong the angioneuroses, acroparsesthesias, angioneurotic oedemas, symmetrical gangrenes, erythromelalgias, acrocyanoses, etc. 1 Vasomotor Relations, The Harvey Lectures, 1906-1907. * Die vasomotorisch-trophischen Neurosen, Berlin, 1901 TROPHIC DISTURBANCES 81 Trophic disturbances may concern the muscles, the bones and joints, the skin, and its appendages. The trophic changes in the bones and joints have been best studied in tabes, in syringomyelia, and in acromegaly. In tabes spontaneous fracture of the bones frequently occurs, and still more frequently certain arthropathies, which occur suddenly, usually without pain, and lead quickly to disintegration of the joints.1 In acromegaly, owing apparently to disease of the hypophysis, there is hypertrophy of many of the bones of the body, especially of the bones of the hands and feet, of the nose, and of the lower jaw. Trophic changes which take place in the skin include bedsores (decubitus), falling of the hair, nails, and teeth in tabes, perforating ulcer of the foot in tabes and syringomyelia, and the panaritium of the finger tips in syringo- myelia. Scleroderma and progressive facial hemiatrophy also belong here. Disturbances of the secretion of the sweat glands and of the sebaceous glands of the skin are sometimes met with in nervous disorders. The anomalies of the secretion of saliva, of the stomach juice, of the urinary secretion, etc., should also be mentioned. As a matter of fact, but little is known as yet concerning the exact mechanisms underlying the vasomotor, trophic, and secretory neuroses. 1 Barker (L. F.). Joint 'Affections in Nervous Diseases, Jour. Amer. Med. Assoc., 1907, vol. i. VOL VII. — 6 CHAPTER II. DISEASES OF THE MOTOR TRACTS. BY WILLIAM G. SPILLER, M.D. PROGRESSIVE SPINAL MUSCULAR ATROPHY. Synonyms. — Muscular atrophy, type Duchenne-Aran ; chronic anterior poliomyelitis. Definition. — By the Duchenne-Aran type of muscular atrophy is meant a progressive muscular wasting related to degeneration only of the cells of the anterior horns of the spinal cord and their peripheral processes. While it usually begins in the small muscles of the hand, it may begin in the muscles of the shoulder, and is even then designated as the Duchenne-Ar,an type. While usually asymmetrical, it may be unilateral for a time. The scapulo- humeral type was first described by Vulpian. History. — Many authors had contributed to the subject of muscular atrophy before the time of Duchenne of Boulogne, and Aran, but the impetus to the study of this condition was given by the writings of these two men. Among the early investigators were Dubois, van Swieten, Abercrombie, Sir Charles Bell, Graves, Darwall, and Cruveilhier. Beevor says the first case recorded was by Sir Charles Bell in 1836. The name of Aran is some- times placed before that of Duchenne and sometimes follows it. A paper was published by Duchenne in 1849, and it was not until a year later that Aran's work appeared. A further study by Duchenne was made in 1853. Both Duchenne and Aran looked upon the atrophy as muscular in origin. The anatomical investigations of Cruveilhier led to the disease being re- garded as atrophy of the anterior roots. Luys demonstrated degenerative changes in the cells of the anterior horns. These and the investigations of Charcot, Joffroy, and others led to the conclusion that all progressive mus- cular atrophy was of spinal origin from disease of the cells of the anterior horns, a view that later was shared by Duchenne, although it was contrary to that he had previously held. The confusion at that period was very great, nor can it be said at the present day that complete order has been brought out of the chaos. Duchenne included all progressive muscular atrophy, whether occurring in families, in young or old persons, or as an acquired process, under one head. Gradually different types of muscular wasting were separated from the Duchenne-Aran form. Progressive muscular dystrophy in the pseudo-hypertrophic form had been observed by Duchenne in 1853, and was clearly established by the writings of Eulenburg, Charcot, Leyden, Mobius, Lichtheim, and Landouzy and Dejerine. Duchenne at first erred in believing the pseudo-hypertrophic muscular paralysis was of cerebral origin, inasmuch as his earlier cases manifested feeble intelli- gence, but later he recognized his mistake. He called the disease paralysie (82) PROGRESSIVE SPINAL MUSCULAR ATROPHY 83 musculaire pseudo-hypertrophique, and the name he gave it has clung to it to this day. Erb established the unity of the various types of myopathy, but at first only the pseudo-hypertrophic and the Leyden-Mobius types were recognized. Charcot separated the amyotrophic lateral sclerosis from the general groups of atrophy. Charcot and Joffroy distinguished the cervical hypertrophic pachymeningitis in 1871 to 1873, although it cannot be said that the symptoms of this disease are so sharply defined as are those of amyo- trophic lateral sclerosis. Charcot recognized as protopathic the atrophy due primarily to lesions of the nerve cells of the anterior horns, and as deuteropathic that resulting from changes within the spinal cord but affecting the anterior horns secondarily. Schultze and Kahler, in 1888, still further weakened the Duchenne-Aran type of muscular atrophy by separating the great group of syringomyelia. It began to look as though nothing would be left in the Duchenne-Aran type, and indeed it is stated that Charcot himself felt that it stood on an insecure foundation. In 1897 Marie came forth boldly in defiance of the accepted teaching. He pointed out that Duchenne at first believed that progressive muscular atrophy was of peripheral origin; later, he believed it to be of spinal origin. The disease at first, as understood by Duchenne, included all the forms of muscular atrophy not resulting from fracture. Marie then described how amyotrophic lateral sclerosis, progressive muscular dystrophy, multiple neuritis, and syringomyelia were separated from the great group of atrophies. Fully one-third of Duchenne's cases, from his own description, Marie thinks, belonged to syringomyelia, although this disease at that time was not recog- nized. Thus, Pierre Marie says that the progressive muscular atrophy of Duchenne-Aran, which earlier authors regarded as the most solid foundation of neuropathology, has ceased to exist. Even the hand which is commonly regarded as of the Duchenne-Aran type is, according to Marie, not the de- formity Duchenne described, and is what Duchenne believed to be character- istic of leprosy. The hand that he described as typical of his progressive muscular atrophy Marie believes belongs to syringomyelia. The atrophy is not so intense, and the fingers are not so much flexed; and yet in comparing the two hands, as pictured by Marie, the differences do not appear very great, and seem to be more in the degree of deformity. Marie, however, believes that Duchenne merely described a symptom complex, and that nothing now remains of his progressive muscular atrophy. Etiology. — Pregnancy may have some influence on the development of spinal muscular atrophy, though it would seem questionable whether it be able to originate it when no tendency to the disease exists. In Oppenheim's second case of chronic poliomyelitis, a complicated case, weakness of the muscles of the right shoulder and of the right upper limb developed during the fourth pregnancy ; the following year the left upper limb became affected during pregnancy. Nonne attributed the poliomyelitis in his second case to diabetes. A case reported by Erb seems to show some relation to trauma. Other authors speak of trauma, notably Ziehen. Heredity does notplay a role,andyet Braining has observed chronic anterior poliomyelitis in father and son, and in one of the cases obtained a necropsy; this family occurrence was probably merely a coincidence. Age seems to be the most important factor, the symptoms usually appear- ing in middle life. The infantile form of progressive spinal muscular atrophy is considered separately. Myelopathy is probably an abiotrophy, to employ 84 DISEASES OF THE NERVOUS SYSTEM a term originated by Gowers, and is the result of an imperfectly developed motor system unable to withstand the stress of advancing years. It is exceedingly questionable whether infections or intoxications cause the symptoms, although the development of progressive muscular atrophy many years after an arrested acute poliomyelitis is regarded by Leri as evidence of this origin. Undoubtedly infection is a cause of the acute form of poliomyelitis, and the nerve cells left weakened by this process may degenerate later in life, but this is not a proof that the chronic form is so caused. Some toxic substance acting on the cells weakened by acute polio- myelitis may cause progressive muscular atrophy. It seems probable that lead may be one of these agents. The acute and chronic forms probably have a very different pathology. The male sex is regarded by certain authors as much more frequently affected than the female. Some of the cases supposed to represent progressive spinal muscular atrophy are caused by myelitis, especially the syphilitic form. The inflammation may be almost confined to the gray matter, and such being the case, sensory disturbance may be absent. The symptoms then would be those of progres- sive spinal muscular atrophy, although the lesion would be a diffuse process of inflammatory character. Pathology. — The characteristic changes are atrophy and degeneration of the nerve cells of the anterior horns of the spinal cord, and also in some cases of the motor nuclei of the medulla oblongata. Sometimes many of the nerve cells entirely disappear. Numerous hemorrhages have been observed in the gray matter in some instances (Bielschowsky, Spiller), ex- tending even throughout the cord. The motor roots are atrophied, and contain fewer fibers than normal. The white matter of the spinal cord remains unaltered in a typical case, or at least the sclerosis is not in the area occupied by the crossed pyramidal tracts. It is questionable whether those cases in which a very slight degeneration of these tracts occurs, detectable only by the Marchi stain, should be classed as progressive spinal muscular atrophy or amyotrophic lateral sclerosis. The symptoms and the findings in the anterior horns may indicate that the lesions of the anterior horns have been of long duration, while the degeneration of the lateral columns evidently is very recent, and no clinical evidence of the slight degeneration of the pyra- midal tracts may have been detected during life. It seems best to regard such cases as belonging to progressive spinal muscular atrophy or chronic polio- myelitis, but as marking a transitional stage to amyotrophic lateral sclerosis. Beevor in disputing the correctness of Gowers' view that amyotrophic lateral sclerosis and progressive spinal muscular atrophy are the same disease, mentions that he (Beevor) has had a case in which the symptoms began with atrophy of the small hand muscles, and later the shoulder muscles became affected, the lower limbs were only slightly implicated. Rigidity or increase of the deep reflexes was not present at any period. Atrophy of the cells of the anterior horns was found, but the lateral columns were intact. Degenerative changes in the anterolateral columns may be recognized as belonging to anterior poliomyelitis and progressive spinal muscular atrophy, provided the pyramidal tracts are not affected. It must be accepted that certain of the column cells may degenerate as well as the cells of the anterior roots. When the pyramidal tracts become implicated the cases are on the border line of amyotrophic lateral sclerosis. Credit has been given to PROGRESSIVE SPINAL MUSCULAR ATROPHY 85 Oppenheim as reporting, in 1888, the first well-described case of chronic poliomyelitis with necropsy. The nerve cells of the anterior horns of the cord, and to some extent those of the medulla oblongata, were degenerated; a slight atrophy was found in the anterolateral columns. The anterior roots were affected, as would be expected, but not to the degree that the cellular degeneration seemed to demand. Perivascular round-cell infil- tration has been seen in some cases (Bielschowsky). It is uncertain whether the cellular changes are primary or secondary. In some instances they may be primary, in others they may be the result of inflammation in the surrounding tissues. Where the process has advanced so far that most of the cells have disappeared, the neuroglia of the anterior horns appears denser and the few nerve cells that remain show much pig- mentation. The cellular destruction is usually greater in the cervical swelling; and the anterior roots usually are much atrophied. The peripheral nerves and muscles show more or less alteration. Syphilitic myelitis probably is the lesion underlying a certain number of the cases of progressive muscular atrophy. Progressive ophthalmoplegia may become associated with degeneration of the motor cells of the medulla oblongata and spinal cord, as in two cases observed by Dana. Cases of progressive spinal muscular atrophy sometimes occur in museums as examples of "living skeletons." Such a case with necropsy. was reported by E. W. Taylor. The nerve cells of the anterior horns had almost entirely disappeared, but the pyramidal tracts were not degenerated. It seems to Dana an unnecessary confusion of symptomatology to transfer the diagnosis of progressive muscular atrophy of the Duchenne-Aran, or other type, to that of amyotrophic lateral sclerosis so soon as a little spasticity begins, especially as there may be nothing peculiar in age, course, or duration. The atrophy may start in the hands and ascend to the shoulders before there is any evidence of lateral sclerosis. The disease may then become arrested, the spastic symptoms disappear, and the patient may again present the type of Duchenne-Aran atrophy without any spastic symptoms. All that we can do, in the writer's opinion, is to acknowledge that the lateral columns may be slightly affected without producing clinical manifestations, but be- cause we cannot always recognize this slight degeneration clinically is not sufficient reason to decline to make distinctions in the pathological forms of spinal muscular atrophy. It is a question whether we are solving the problem by following Dana in limiting the use of the term amyotrophic lateral sclerosis to those cases which show only from the beginning and dominantly the spastic and contracturing type of progressive muscular atrophy. Why must degeneration of the lateral columns develop previously to or simultaneously with disease of the cells of the anterior horns, and not later? Symptoms. — The symptoms of chronic anterior poliomyelitis and pro- gressive spinal muscular atrophy vary in typical cases. In the former the paralysis is supposed to develop within a few days or a few weeks, the atrophy appears later, and entire muscles or groups of muscles are paralyzed, the course of the disease is more rapid, and the paralysis develops first in the muscles of the lower limbs or shoulders. In progressive spinal muscular atrophy, the paralysis is proportional to the atrophy, one muscle fiber after another is affected, and the course is longer than in poliomyelitis. These distinctions are not always regarded, and some of the reported cases of gg DISEASES OF THE NERVOUS SYSTEM so-called poliomyelitis might with greater right be regarded as examples of progressive spinal muscular atrophy, or even as transitional forms to amyo- trophic lateral scleroses. Dejerine and Thomas, who describe the disorder under the name of chronic anterior poliomyelitis, say that atrophy is the primary and essential symptom, and paralysis is secondary and proportional to the atrophy. Thus, accord- ing to these authors, one of the most important diagnostic points between chronic poliomyelitis and progressive spinal muscular atrophy disappears. Beevor, likewise, makes no sharp distinction between the two processes, and remarks that wasting may begin in the lower limbs. The first indication of disturbance may be awkwardness in the use of one or both hands. Usually one is affected before the other. Abduction and apposition of the thumb with the other fingers become affected, then the interossei and lumbricals waste, and the whole hand becomes much atrophied, including the thenar and hypothenar eminences. The tendons of the palm become very prominent. When the thenar eminence is wasted the hand is of the simian type. Later, when the interossei and lumbricals are attacked the flexion of the phalanges upon the metacarpal bones and the extension of the phalangeal articulations become impaired, so that the first phalanges are extended and the second and third flexed, the palmar tendons are prominent (main en griffe). The atrophy gradually extends to the flexors on the forearm, then to the extensors. According to Beevor, the flexors of the fingers and thumb are affected before the flexors of the wrist. The atrophy reaches the deltoid and muscles of the upper part of the limb and shoulder girdle. Beevor states that the triceps, latissimus dorsi, and the lower half of the pectoralis major usually escape. The trunk and neck muscles waste and the ribs become prominent; the lower limbs likewise become greatly atrophied. Dejerine and Thomas dispute the extension of the process to muscles innervated by bulbar nerves, as no necropsy has demonstrated such an extension, and they assert that the face is always intact, and Dejerine believes that bulbar palsy belongs to amyotrophic lateral sclerosis. Beevor, however, speaks of bulbar paralysis as a part of chronic anterior poliomyelitis, and Leri also mentions atrophy of the muscles of the face, although he adds that the condition is very different from that of bulbar palsy. Quite a number of cases are recorded in which the atrophy began in the lower limbs, especially in the peroneal distribution, and in some instances (Moleen and Spiller) the weakness and atrophy developed rapidly. The upper limbs became implicated later. In other cases the muscles of the shoulder girdle are first affected (Vulpian, Dejerine) or the extensors of the fingers and wrists, as in a case reported by C. S. Potts. The muscles of the trunk may be first affected. The weakness and atrophy probably begin more commonly in the hands, because the movements of these parts are highly differentiated; it is not probable that the weakness is first noticed in muscles employed frequently in specialized movements simply because the interference with these move- ments is more striking to the patient, and that in reality other muscles are affected at the same time. Edinger's exhaustion hypothesis, that those muscles most used are most likely to be the first to show alteration, is a reasonable explanation for the commencement of the symptoms in the hands in most cases. The paralysis is flaccid and. the joints are relaxed, PROGRESSIVE SPINAL MUSCULAR ATROPHY 87 producing the condition known as flail joint, especially noticeable at the wrists. Grunow and Loevegren go so far as to make the atrophy of the lower limbs the first sign diagnostic for poliomyelitis in distinction to pro- gressive spinal muscular atrophy. Fibrillary tremors are very common in the atrophying muscles ; sometimes they implicate small bundles of muscle fibers, and then they may more properly be described as fasciculary. These quick, wave-like movements are not present in the atrophying muscles at all times, but in most cases may be detected at some period or other. They may be so pronounced as to correspond to the condition known as "muscular madness" (folie muscu- laire), but they do not cause movement of a segment of the limb, unless possibly of a finger. They are an early sign, and disappear as the atrophy of the muscles becomes intense. They may be present at one period in spinal atrophy, but later disappear, so that the absence of fibrillary tremors by no means excludes a spinal origin. The tendon reflexes of the affected limbs become diminished or lost, and may be lost before atrophy appears, the cutaneous reflexes become less active where the muscles are wasted. Exaggerated reflexes should make the diagnosis of progressive spinal muscular atrophy or chronic anterior poliomyelitis doubtful, but, according to certain authors, do not exclude this diagnosis. Thus Oppenheim does not regard exaggeration of the tendon reflexes as sufficient to make a case of muscular atrophy one of amyotrophic lateral sclerosis. The electrical reactions are important in the diagnosis between the myelopathic and the myopathic forms of muscular atrophy. In the latter the irritability is diminished, but the formula is not altered ; in the former the nerves may respond to the faradic and galvanic currents, although not in the same degree; later the response to either current may be lost. The muscles at first require a stronger current, then their faradic irritability may be lost; when the galvanic irritability is increased, the formula may be reversed, so that the anodal closing contraction is equal to or greater than the cathodal closing contraction (reaction of degeneration); still later all electrical irritability of the affected muscles may be lost. Especially valuable as a sign of myelopathy is the modal change, so that the muscles contract very slowly to the galvanic current. The entire muscle does not always show electrical alteration, and only a few fibers may present this change, while adjoining fibers in the same muscle are normal; this is because fibers much atrophied may be in juxtaposition to normal fibers. Sensory changes are not a part of myelopathy. Objective disturbance of sensation does not occur in an uncomplicated case, and while pain may occasionally be complained of, it is of a peculiar kind; it is the pain from overuse of wasting muscles, and not that from irritation of sensory fibers. It is more a dull aching like that in fatigued muscles, and not sharp, such as is felt in toothache. Some authors speak of pain occurring in the beginning of myelopathy, but skepticism, as regards the correctness of the diagnosis is justifiable when pain is intense. The sphincters of the bladder and rectum escape, but theoretically one may understand how they could become affected if the nerve cells of the conus were degenerated. Atrophy of bone has been described by some authors. Cutaneous lesions are probably epiphenomena. Vasomotor symptoms may be present, and the atrophied limbs may be cold. gg DISEASES OF THE NERVOUS SYSTEM Progressive spinal muscular atrophy may develop on a foundation of old arrested acute poliomyelitis. C. S. Potts has paid particular attention to muscular atrophy occurring in this way, and has collected the records of 36 cases. In 28 the condition was probably progressive muscular atrophy; in 2, amyotrophic lateral sclerosis; in 2, myelitis; and in 4, another attack of acute poliomyelitis. The interval elapsing between the primary and second- ary attacks ranged from seven years to about fifty-five years, the average being about twenty-three years. In 18 cases out of 33, in which the part secondarily affected could be determined, the late atrophy began in a limb which had previously been affected by the primary disease; in 7 it began in the other limb on the same side that had been primarily affected ; in 5 in the corresponding limb of the side opposite to the part first affected; in 2 in a limb of the opposite side not corresponding to the limb first affected; and in one the involvement was general, this being a case in which acute polio- myelitis occurred a second time. The most plausible explanation for this late extension is that nerve cells are left in a weakened condition by the acute anterior poliomyelitis, and readily succumb to any damaging process. Chronic external ophthalmoplegia is probably a form of progressive .muscular atrophy of the central type. It is a progressive paralysis of the external ocular muscles. Numerous cases are recorded in the literature. It is usually a disease of infancy, but may develop later in life. Diagnosis. — Remembering the pathology we understand why the symp- toms are muscular atrophy, weakness, loss of reflexes, and changes in electrical reactions. The process is slow (progressive muscular atrophy) or in periods of exacerbations (subacute or chronic poliomyelitis). Progressive muscular dystrophy is to be distinguished by the age at the onset, the involvement first of the proximal parts of the limbs, the hereditary or family tendency, the absence of fibrillary tremors and of reaction of degeneration, the presence of pseudo-hypertrophy, etc. Amyo- trophic lateral sclerosis is clinically progressive spinal muscular atrophy or chronic poliomyelitis with exaggeration of tendon reflexes, and patho- logically with degeneration of the cells of the anterior horns and peripheral motor fibers and the pyramidal tracts; the latter causes exaggeration of the tendon reflexes. Multiple neuritis is usually associated with spontaneous pain, objective sensory disturbances, and tenderness of nerve trunks. The onset is usually more rapid, and the symptoms may be confined to the distribution of certain nerves. Acute poliomyelitis is to be recognized by signs of infection and rapid development of symptoms. The paralysis at first may be extensive, but gradually certain of the affected muscles recover, leaving others permanently paralyzed. Syringomyelia has the dissociation of sensation, impairment or loss of temperature, and pain sensations, with much better preservation of tactile sensation; also trophic disturbances, and it may be more nearly unilateral. The neurotic muscular atrophy of Charcot, Marie, and Tooth may closely resemble chronic poliomyelitis, but where sensory disturbances are present the distinction is clear. It is likely to be hereditary, and is more common in males. The atrophy is confined to the peripheral parts of the limbs, even after many years. Leprosy may have some resemblance in that it may begin in the hands and extend toward the trunk in the upper limbs, implicate the lower limbs in a similar manner, and be associated with reaction of degeneration. The lepra bacillus in the tissues, the dissociation of sensation like that of syringomyelia, the local PROGRESSIVE SPINAL MUSCULAR ATROPHY OF CHILDHOOD 89 swellings in the nerves, and the history of contagion make the diagnosis possible. Cervical hypertrophic pachy meningitis may cause an atrophy of the hands like that of progressive spinal muscular atrophy, but there is a period of pain in the upper limbs with objective sensory disturbances. Prognosis. — Arrest is possible, but improbable. The weakness and atrophy are likely to extend until a large portion of the body is affected, or muscles of vital function, as those of respiration or of the heart, are attacked, or death occurs from some intercurrent disease, but usually the process is very slow, and in one of Dejerine's cases the symptoms lasted about sixteen years. Treatment. — This is of little value. Electricity, especially in the form of the constant current, moderate exercise, and passive movements are recommended and may be useful. Tonics and exercise in moderation help to keep up the general strength, but nothing will restore the muscles atrophied from degeneration of their nerve cells, or probably have much effect in arresting the course. PROGRESSIVE SPINAL MUSCULAR ATROPHY OF CHILDHOOD, OF FAMILIAL OR HEREDITARY CHARACTER (TYPE WERDNIG-HOFFMANN) . History. — The first cases were described by Werdnig, who reported 2; Hoffmann followed, with a report of 20 cases; Thomson and Bruce, with 1 case; Bruns gave, in 1901, a description founded on the cases in the literature to that date. Hoffmann's cases occurred in three families; he examined 6 clinically, 2 anatomically. Both of Werdnig's cases were with necropsy, and occurred in the same family, the patients had the same mother but different fathers. In Hoffmann's third family the disease was evidently transmitted through the mother. Bruns' 3 cases came from three different families. The family character was evident in the first case, as two of the other offspring of the parents had died from the same disease. Nothing concerning family tendency could be determined in the second case. The third patient was the only one affected of four children. Although 2 of his 3 cases manifested no family tendency, Bruns classifies them under this type, as Bruce's case also was the only one in the family. The cases of Bruns, added to those of Werdnig, Hoffmann, and Bruce, make 28 cases in the literature, of which only 12 were observed by physicians. To these should be added 2 cases without necropsy observed by Senator. The cases of Werdnig and Hoffmann began between the sixth and ninth months; only a few of the children could stand before the disease began, and none could walk. Death occurred in the most rapid case in the eleventh month; in the slowest in the fifth year. Bruns' first patient could walk when about a year and three-quarters old, and died in the fifteenth year. His third patient also could walk when about one year and one-quarter old, and was still alive in the twelfth year. Senator's two cases were in brother and sister. The symptoms began in both at about the age of two years. Hoffmann has attempted to classify the cases of hereditary progressive spinal and bulbar muscular atrophy, and makes the following types: 1. Occurrence in early childhood. Implication first of the pelvic girdle 90 DISEASES OF THE NERVOUS SYSTEM and atrophy extending from there toward the ends of the limbs (Werdnig, Hoffmann). 2. The bulbar paralytic facial type of childhood (Fazio, Londe). 3. A Duchenne-Aran type (Striimpell, Gowers). 4. An intermediate form (Bernhardt), which Bernhardt regards as of spinal and bulbar origin. It seems to the writer that the atrophy of Werdnig-Hoffmann may be regarded clinically as progressive spinal muscular atrophy, differing from the usual type seen in adults in the commencement within the first years of life, in the implication first of the pelvic girdle and portions of the limbs near the trunk, and in the strong hereditary tendency, a tendency very feebly manifested in the progressive spinal muscular atrophy of adults; but pathologically the disease is amyotrophic lateral sclerosis of childhood, differing from the type in adults by the absence of exaggeration of tendon reflexes, by which we may infer that the peripheral motor segments are always involved first. The case of Thomson and Bruce shows that they alone may be affected. Pathology. — The findings described by Hoffmann are: Symmetrical intense degeneration of the peripheral neurones of all the motor fibers below the hypoglossus, including the accessorius, i. e., degeneration or disappear- ance of the multipolar cells of the anterior horns, so that few are left in a transverse section; intense degeneration of the anterior roots of the spinal cord, less intense changes in the peripheral nerves and the intramuscular nerve endings; degeneration of the crossed and direct pyramidal tracts, and of a portion of the lateral fundamental columns of the cord, more intense in the upper thoracic and cervical regions, but not traceable above the pyramidal decussation. The muscles show simple atrophy in all stages without complete disappearance of fibers, without multiplication of the sarcolemma nuclei, and with very little lipomatosis of the muscles. There seems to be rather a decrease in the number of muscle nuclei. The transverse striation of the muscles is preserved, but some of the muscle fibers may completely disappear. The alteration of the spinal cord is more intense than that of the muscles, so that the disease in Hoffmann's opinion is spinal in origin. In one case the anterolateral column was not degenerated (Werdnig). In only two of the four cases was lipomatosis found, and in one (Werdnig) homogeneous and granular degeneration of the muscle fibers was observed. Symptoms. — The description given by Bruns is as follows: The dis- ease begins in early childhood, progresses slowly, without fever or convulsions. The children never learn to walk, or gradually lose the ability to walk if they learned before the symptoms began. They cease to move the lower limbs in bed and to hold the trunk erect. Standing becomes difficult, and is possible only in the beginning of the disease, and then only with support. Paresis and atrophy of muscles occur nearly simultaneously in the muscles of the pelvic girdle and trunk, implicating symmetrically the iliopsoas and quadriceps femoris, and later the upper limbs and neck muscles. The proximal portions of the limbs, shoulder girdle, and pelvic girdle are affected, and the atrophy and weakness diminish toward the hands and feet, although these parts do not entirely escape in the late stages, but their movements are better than would be expected from the atrophy. The erect position of the head and trunk is difficult to maintain; the child cannot lie down slowly, AMYOTROPHIC LATERAL SCLEROSIS §1 and raises itself with difficulty. The vertebral column is distorted because of muscular weakness. The feet are in the position of talipes equinus. The atrophy is en masse, and may be partly concealed by fatty tissue. Diminished electrical response or reaction of degeneration is observed in the paralyzed muscles. Fibrillary tremors are present in some cases, absent in others. The bulbar muscles are occasionally affected. Hypertrophy or pseudo-hypertrophy does not develop. The paralysis is flaccid, the tendon reflexes are absent, and contractures occur. There are no sensory or mental disturbances, or impairment of the sphincters of bladder and rectum. The course is rather rapid, and death results from paralysis of the muscles of respiration. The disease is progressive, the progress of the atrophy is from the parts near the trunk to the peripheral portions of the limbs, and the atrophy is entirely symmetrical. Hoffmann believes that fibrillary tremors do not occur, mental development is not arrested, and the muscles of face, tongue, and throat are not paralyzed. Diagnosis. — The greatest difficulty is in regard to muscular dystrophy, and so true is this that Senator says of his two cases that when the children were seen dressed and their mode of sitting, lying down, and standing up (climbing upon the lower limbs as in muscular dystrophy) was observed, the diagnosis of pseudo-hypertrophy seemed correct, but when the clothes were removed no hypertrophy was visible. Most important in the diagnosis were the presence of fibrillary tremors and diminution in the electrical response, and possibly a commencing reaction of degeneration in one case. The cases were without necropsy, and it seems questionable to which type they belonged. The type of Werdnig-Hoffmann shows a more rapid ex- tension of the atrophy than occurs in progressive muscular dystrophy. Congenital myatonia (congenital hypotonicity of the muscles) differs in being a congenital disorder, in the absence of heredity and family tendency, and in the much greater involvement of the trunk and portions of the limbs near the trunk at a very early age. AMYOTROPHIC LATERAL SCLEROSIS. History. — If it be ever justifiable to employ the name of a man in the designation of a disease, it is especially so in regard to amyotrophic lateral sclerosis. Charcot described the affection so fully that Marie has likened his description to the origin of Minerva fully equipped from the head of Jupiter. The French are fond of calling the disorder Charcot's disease. The great French neurologist first directed attention to it in 1865, and in connection with Joffroy wrote on it in 1869, and with Gombault in 1871. In the years 1872 to 1874 he described the disease still more fully. Gom- bault made a further publication in 1877, and later with Debove, in 1879. Dejerine pointed out the relation of amyotrophic lateral sclerosis to the labio- glosso-laryngeal paralysis of Duchenne. In this chapter amyotrophic lateral sclerosis is considered as distinct from progressive spinal muscular atrophy and from chronic or subacute poliomyelitis. Etiology. — Amyotrophic lateral sclerosis is probably an abiotrophy. The individual is born with a certain potentiality of his motor system, but at middle age the strain becomes too great and degeneration begins. 92 DISEASES OF THE NERVOUS SYSTEM There is very little to warrant the opinion that the disease is of toxic origin. It is possible that lead may be a cause, or at least it may cause a symptom complex very closely resembling that of this disease, as shown by S. A. K. Wilson. This author has studied four cases in which chronic lead poison- ing began with double wrist drop, and in three of these the small muscles of the hand were not affected until late in the process, and in the other they escaped so long as the patient was under observation. In all four cases the atrophy was progressive, and was associated with some exaggeration of the tendon reflexes. Babinski's reflex may be found in this lead palsy associated with a certain degree of spasticity and with ankle clonus. The electrical reactions may be altered quantitatively but not qualitatively, and sensation may be intact, although in one of Wilson's cases lancinating pains were present, and this occurrence in association with the Argyll-Robertson pupil led to a diagnosis at first of tabes. No necropsies have been obtained, and, therefore, it is not known whether lead may produce exactly the changes of amyotrophic lateral sclerosis. It is not unreasonable to assume that lead poisoning may appear as a systemic disease of the nervous system, and there is even a possibility that it may assume the type of tabes dorsalis, as shown by a case reported by Redlich. The commencement of the paralysis in the extensors of the hands and fingers is unusual in amyotrophic lateral sclerosis, but does occur. Mus- cular pains are not uncommon in lead poisoning, and cramps sometimes are felt in amyotrophic lateral sclerosis. An Argyll-Robertson pupil is rare in the latter disease, but Wilson seems to have observed it three times. The attempt to give causes for which there is no evidence is hardly a justifiable procedure. We have no reason to believe that traumatism, exposure to cold and wet, or sexual excesses play a role. The occurrence of some trauma shortly before the first symptoms are noticed, as in Naka's case, is no proof that these are caused by the trauma. It is not probable that syphilis causes amyotrophic lateral sclerosis. Syphilitic disease of the cord may produce a clinical picture resembling it, in that there may be spasticity, weakness of the limbs, atrophy of the small muscles of the hands, exaggerated tendon reflexes and fibrillary tremors. Careful examination, however, will usually reveal other symptoms; thus there may be severe pain in different parts, or disease of the optic nerves; or the history may mention the sudden onset of a hemiplegia, perhaps transitory. The writer has studied such a case, in which many of the symptoms suggested amyotrophic lateral sclerosis. Frequency of Disease and Sex Involved. — Raymond and Cestan reported, in 1905, 18 cases with necropsy in the service of the former at the Salpetriere; 13 were in men and 5 in women. In Collins' cases, 55 were males and 49 females. Probst, in 1898, found that of 53 cases the number was evenly distributed between males and females. Heredity and occupation do not seem to exert any influence. The writer has reported 8 cases of primary degeneration of the central motor tracts with necropsy; 2 of these belong to the type of primary lateral sclerosis, as the nerve cells of the anterior horns of the spinal cord escaped, and in neither of these cases was muscular atrophy present. Amyotrophic lateral sclerosis seems to be a rare disease, about as rare or possibly more so than syringomyelia, but not so infrequent as some observers believe. AMYOTROPHIC LATERAL SCLEROSIS 93 Pathology.— Amyotrophic lateral sclerosis is a degeneration of the pyramidal tracts, of the nerve cells of the anterior horns of the spinal cord, of the anterior roots, intramedullary and extramedullary portions; of the peripheral nerves, of the muscles, and sometimes of the nerve cells and fibers in the motor cortex. The corpus callosum and the posterior longitudinal bundles may be affected. It is essentially a death of the motor system and muscles. The fibers that stained by hematoxylin in the pyramidal tracts of the spinal cord in this disease were noticed by Charcot and Marie to be very fine. Anton also observed an unusual number of fine fibers in the pyramidal tracts, and a similar observation was made by the writer, although fibers of larger size were mingled with these small fibers. The latter in the sclerotic tracts suggest that atrophy as well as degeneration of nerve fibers plays a role, but the Marchi method indicates very clearly that degeneration of the myelin sheaths is very important. The central motor tracts develop from above downward, and the terminal portions being the last formed are the least resistant, and, therefore, degenerate first. The degeneration of the pyramidal tracts is not so intense in amyotrophic lateral sclerosis as in the sclerosis resulting from a cerebral lesion. This is probably because one fiber after another is attacked in the process, and all do not begin to degenerate at the same time. There is some doubt whether the process in most cases is ascending in each nerve fiber attacked, and the mere cessation of the degeneration at a certain level is no proof of an ascending process. It is reasonable to believe that there is a gradual death of the portions of the central motor neurones most remote from the cells of origin, and that the extent of the degeneration varies in different cases, but that the whole portion that is affected in each fiber is diseased usually almost simultaneously, although the individual nerve fibers are attacked at different periods. Hoche's findings would seem to indicate that the degeneration of the pyramidal tracts may be ascending, but this observation has not been matched, and we cannot conclude that the ascending degeneration has been demonstrated as the general rule. Kojewnikoff was the first (1883) to trace degeneration of the pyramidal fibers from the lower end of the cord to the cerebral hemisphere. In the two hemispheres the "corps granuleux" (fatty granular cells) were in per- fectly symmetrical areas, and in almost equal quantity on the two sides. Charcot and Marie (1885) traced the degeneration to the motor cortex in two cases. Kojewnikoff (Koschewnikoff) in a second case found degener- ated fibers throughout the central motor tracts, and did not depend merely on the presence of fatty granular cells. In Lennmalm's case the pyramidal tracts were said to be degenerated from the cerebral cortex throughout their extent. Lumbroso traced the degeneration to the cortex. Striimpell could not follow the degeneration of the pyramidal tract above the superior part of the inner capsule, and he was unable to detect pathological changes in the nerve cells of the motor cortex. Mott traced the degeneration by Marchi's method through the inner capsule and into the motor cortex. Hoche, by the same method, traced degenerated fibers into the central gyri. Rossi and Roussy, in 1907, found 18 cases on record in which the degenera- tion had been traced to the cortex. As regards the degeneration of the pyramidal tracts the writer has been 94 DISEASES OF THE NERVOUS SYSTEM able to trace degeneration of the tracts as high as the motor cortex in one case, as high as the internal capsule in 2 cases, as high as the cerebral peduncle in 2 cases, as high as the pons in 3 cases. The degeneration does not usually extend above the pons, and gradually disappears. The higher regions of the pyramidal tracts show a more normal manner of staining. In one case degeneration of the pyramidal tract was traced on one side as high as the pons, and on the other as high as the lower part of the internal capsule. The degeneration therefore is not always symmetrical on the two sides, although it usually is. The writer has observed great spasticity of the limbs when the degeneration of the pyramidal tracts was barely detect- able. The weakness may be due entirely to implication of the central motor tract alone, but the writer has observed paralysis on one side greater when the degeneration of the pyramidal tract on the same side was less intense than that of the other side. A study of the nerve cells showed that the motor cells of the spinal cord on the side of the less affected pyramidal tract were the more diseased. Marie has stated that the degeneration of the lateral columns involves a greater area than that occupied by the pyramidal tracts, as shown by secondary degeneration from cerebral lesions or by myelination of the cord. It is unquestionable that the degeneration does extend beyond the pyra- midal tracts, and this alteration of the supplementary zone has been described in progressive spinal muscular atrophy by J. B. Charcot. As in this disease, the pyramidal tracts are not degenerated, it is evident that this supplementary zone is not a part of the pyramidal tract. Degeneration of this zone does not occur in every case of progressive spinal muscular atrophy. Pilcz found degeneration by the Marchi method in the anterolateral columns much greater than in the pyramidal tracts. This would indicate that the fibers in the former were more recently affected, and the condition in this respect resembles the degenerative changes occurring in the spinal cord in cases of grave ansemia. There is, however, another explanation. The fibers of the pyramidal tracts extend a long distance, and when they are degenerated the change is seen through a great part of these tracts, and has the appearance of long-standing alteration; whereas in the antero- lateral column? the fibers are much shorter, and many more fibers must degenerate to cause a long-standing alteration as intense as that of the pyra- midal tracts, but there may be more fibers in a stage of acute degeneration. The anterior horns may contain fewer fibers than normal; the cells of the anterior horns may be much affected, in some the nucleus may be displaced to the periphery, and the chromophilic elements entirely destroyed, except where they surround the nucleus, and the remainder of the cell may have a pale green appearance by the theonin stain. The pigment is sometimes much increased. In some cells the nucleus may disappear, in many the chromophilic elements are changed to fine granules. Many cells have no dendritic processes, or only imperfect ones; some of the cells are tumefied and rounded, some have altered cell bodies and normal dendritic processes, in some cells a faint, bluish tint along the periphery is all that is left of the chromophilic elements. The bulbar changes are often pronounced. The nuclei of the hypoglossal nerves may be much degenerated or even disappear, so that the cells may be few in number, with chromatolysis and much pigmentation, and loss AMYOTROPHIC LATERAL SCLEROSIS 95 of dendritic processes; or they may entirely disappear. The intramedullary fibers of the hypoglossus may be intensely degenerated. The tongue muscles may be greatly wasted, in association with the alteration of the hypoglossal nerve, and show excess of interstitial fatty tissue. The nucleus ambiguus, as well as the posterior nucleus of the vagus nerve, may be much degenerated, but as the cells of the former do not form a very sharply defined group, it is often difficult to determine a partial destruction of this nucleus. The fibers arising in this nucleus may be few in number. The soft palate may be wasted. The motor nucleus of the trigeminal nerve has been found affected (Rossi and Roussy, and others), but may escape when other bulbar nuclei are dis- eased. The facial, the glossopharyngeal, and spinal accessory nerves, and their nuclei, may share in the alteration. The nuclei of the ocular muscles, according to Marie, are never affected in this disease, but Hoche has found degeneration of the oculomotor, trochlear, and abducent nerves, and this indicates that ophthalmoplegia might occur. Bulbar symptoms, however, may exist without distinct alteration of the bulbar nuclei. The microscopic examination of a case reported by Dercum and the writer showed that the bulbar nuclei were for the most part intact, but the degeneration of the pyramidal tracts extended above these nuclei. It is possible that nerve fibers controlling these bulbar nuclei were affected, and this would seem to support Charcot's view of the process as primarily a degeneration of the pyramidal tracts. Oppenheim observed symptoms of disease of the ninth, tenth, and eleventh nerves in amyotrophic lateral sclerosis without changes in the nuclei of these nerves. The bulbar nuclei, on the other hand, may be affected without implication of the pyramidal tracts. Duval and Raymond have reported a case in which the bulbar nuclei were affected and no trace of sclerosis of the motor tracts was seen. Raymond refers to a number of other cases in which the nuclei were affected but the motor tracts escaped. Miura asserts, however, that no case of progressive bulbar palsy without degeneration of the pyramidal tracts is to be found in the literature. It occurred to the writer in 1899 that inasmuch as amyotrophic lateral sclerosis is a disease of the motor system, a case in which the cortex was degenerated could be employed in delineating the extent of the motor area in man. The process seemed almost like an experiment. This use of amyotrophic lateral sclerosis was original with the writer, and later was adopted by others. Intense degeneration of the precentral convolution was found and considerably less degeneration of the postcentral convolu- tion, and therefore it was concluded that the latter is also a part of the motor cortical area. The postcentral convolution may escape. It is proper to state, however, that the tendency is to exclude the postcentral convolu- tion from the motor region. Degeneration of the corpus callosum has been found by Probst, Spiller, Rossi and Roussy, and Naka in the middle portion of this structure. In the writer's case it extended in less intensity to the knee. The large cells of the motor cortex have been found diseased. Mott found that many of them had disappeared. Marinesco has found the giant cells of the motor cortex greatly diseased. Most of these cells had dis- appeared, and the few remaining were atrophied, and had undergone chromatolysis and displacement of the nucleus. Kojewnikoff noticed atrophy and pigmentation of these cells. 96 DISEASES OF THE NERVOUS SYSTEM Some degeneration of the columns of Goll in the cervical and upper thoracic regions has been observed in a case of primary lateral sclerosis reported by Dejerine and Sottas. Sensation had been normal. Moeli observed degeneration of these columns in these regions in a case of amyo- trophic lateral sclerosis. The columns of Goll are very liable to undergo a slight sclerosis in the lower cervical and upper thoracic regions in cases where no symptoms of this sclerosis have been present, and in some way it seems to be related to disease of the central motor tracts. Oppenheim, and Charcot and Marie have noticed sclerosis of these columns in amyotrophic lateral sclerosis. These cases must be distinguished from those in which the symptoms of posterior sclerosis were added to those of sclerosis of the lateral columns, a posterolateral sclerosis. Nonne has observed a distinct though not exces- sive rarefaction of fibers in the median portion of the posterior columns in chronic anterior poliomyelitis ; it was most evident in the cervical region. The degeneration of the posterior columns in these cases of primary degenera- tion of the motor system is not tabetic in character, it is not systemic. The posterior roots are not degenerated, and the region affected, lower cervical and upper thoracic, is not that usually diseased in tabes. It was present in the case described by Dercum and the writer. In only two of Raymond and Cestan's cases was a slight sclerosis of the columns of Goll in the cervical region observed, and as these patients were sixty-one and sixty-eight years old respectively, the authors are inclined to attribute it to old age. The muscles may be intensely atrophied, but even in many of these atro- phied fibers the transverse striation may be distinct; in others the longitudinal striation may be more visible. The muscle fibers may or may not show fatty degeneration. In some of the fibers striation may not be clearly seen. The vessels may be much altered. Much fatty tissue may be found in some parts of the field. The nerve fibers between the muscular fibers may appear normal. The ulnar nerve has been found degenerated in one case (Spiller). Symptoms. — Amyotrophic lateral sclerosis is a disease of middle life. Marie regards those cases (Erb, Seeligmuller) in which it is said to have begun in childhood as very doubtful, and he believes that some of them belong to the family spastic paralysis. Marie gives the commencement between the ages of thirty-five and fifty years; Dejerine, the second half of adult life; Oppenheim, middle life; Eichorst, between thirty-five and fifty years; Gowers, between twenty-five and forty-five years; Striimpell, between twenty-five and forty years. In Probst's statistics of 47 cases the disease began most frequently between thirty and fifty years, in 13 cases between fifty and sixty years, in 5 cases between sixty and seventy years, and in one case after seventy. Rossi and Roussy conclude that the beginning is usually between thirty and fifty, although frequently between fifty and sixty years; it is rare between sixty and seventy, and exceptional after seventy years. They have not been able to find any case recorded with a commencement after seventy years, except one case of Probst, but they report two cases from the service of Pierre Marie in which the commencement was at the seventy-first and seventy-third year. Marie fixes the duration at eighteen months to two years, but death may occur in three to six months. Dejerine has observed a duration of nine years, and Florand of ten years. Marie questions whether these were truly PLATE I Amyotrophic Lateral Sclerosis. With bulbar symptoms and preater implication of the proximal part of the upper limbs, in a boy, aged nineteen years. (Spiller and Gittings.) AMYOTROPHIC LATERAL SCLEROSIS 97 cases of amyotrophic lateral sclerosis. Collins selected the records of 94 typical cases, and added to these 10 of his own cases, but not all these were with necropsy. He found that in 100 selected cases, 30 patients were be- tween thirty and forty, 29 between forty-five and fifty, 28 between fifty and sixty, and 2 under thirty. In 26 cases the average duration was a little more than two years. The briefest duration was five months, and the patient died from influenza, so that the case may be rejected so far as its duration was concerned. In 2 cases the disease seems to have terminated in six months. Records of 4 cases were found in which the disease lasted only nine months. A few cases lasted only about five years; the longest on record was ten years. Amyotrophic lateral sclerosis may begin occasionally at an early age. The writer has seen, in association with Dr. Gittings, a boy, aged nineteen years, who had marked bulbar symptoms with signs of degeneration of the nerve cells of the anterior horns in the cervical and thoracic regions, and possibly slight degeneration of the pyramidal tracts. The course was rapidly fatal, the symptoms being present only about one year. The symptoms were first manifested in two of the writer's cases in one lower extremity, although in one of these the upper limb of the same side may have been implicated at nearly the same time. The paralysis in these two cases became a hemiplegia and later a triplegia. In another case the paralysis seemed to begin as a hemiplegia. The statements of the patient or of the relatives must be taken in determining the part first affected, and there is, therefore, an element of doubt; The weakness and atrophy usually begin in the muscles of the hands, but sufficient cases are on record to show that they may commence in the feet. In a case reported by Dercum and the writer the weakness of the lower limbs preceded the bulbar symptoms about three years. In 81 cases collected by Collins, the upper extremities were first involved in 39 cases, the lower in 14 cases, the limbs of one side in the hemiplegic type, or all four limbs in 11 cases. The writer collected reports of 11 cases (Dejerine, Pick, Vierordt, Leyden, Lennmalm, Mott, Senator, Probst (4) ) in which the symptoms were con- fined to one side of the body, although both pyramidal tracts were affected in some of these cases. A case reported by C. S. Potts should be included in the list. Where the disease begins as a unilateral affection it does not remain as such, but sooner or later, and usually soon, the other side of the body becomes implicated. The shoulder muscles in rare instances may be affected first, and Dejerine and Thomas report two such cases, or the ex- tensor muscles of the hand may be first affected. Raymond and Cestan1 from a study of their cases make four types of amyotrophic lateral sclerosis: (1) Ordinary spinal type; (2) labio-glosso- laryngeal paralysis; (3) amyotrophic type; (4) spastic type. 1. Ordinary Type. — This corresponds to the classical description of Char- cot with spastic paraplegia or tetraplegia, ankle clonus, later amyotrophy, fibrillary tremors, and disturbances in the electrical reactions. Babinski's reflex was not observed, which seems to be remarkable. Only three of their cases corresponded to this type, and in two of them the amyotrophy began in the lower limbs and later implicated the upper limbs and the muscles innervated from the medulla oblongata. In one case the amyotrophy began 1 Raymond and Cestan, Revue Neurologique, 1905, p. 504. VOL. vn. — 7 98 DISEASES OF THE NERVOUS SYSTEM in the hands. These cases lasted twenty-four, twenty-six, and twenty-six months respectively. 2. Labio-glosso-laryngeal Type. — This was observed five times, four times in women, and Raymond and Cestan are inclined to think it is more com- mon in this sex. The affection began in the muscles of the lips, tongue, and larynx, with exaggeration of the masseter reflex. Soon the limbs be- came implicated with exaggeration of the reflexes and progressive amyo- trophy of the upper limbs. One patient had in the beginning attacks of choking, probably from spasm of the glottis; another had spastic laughing and weeping, without impairment of intellect. The cord showed degenera- tion in the anterolateral columns of the cervical and thoracic regions by the Marchi method. The duration of these five cases was from fourteen to twenty-four months. 3. Amyotrophic Type. — The disease appears as progressive muscular atrophy. The spasticity is slight, and ankle clonus and Babinski's sign are not obtained, but the bony and tendon reflexes are exaggerated, some- times only slightly. The slight spasticity makes the diagnosis somewhat doubtful. The duration ranged from eight months to five years. The diagnosis must be made from the Duchenne-Aran type of muscular atrophy and subacute anterior poliomyelitis, but the necropsies showed degenera- tion of the anterolateral columns. Nine of their cases were of this type. The disease of the peripheral motor segments is prominent in this type, but the implication of the central motor segments is indicated by some exaggeration of the tendon reflexes, although spasticity is slight or even absent. It resembles subacute anterior poliomyelitis very closely, and, indeed, several of the cases of this latter disease with necropsy that have been reported belong to the non-spastic type of amyotrophic lateral sclerosis, as pictured by Raymond and Cestan. 4. Spastic Type. — Only one of Raymond and CestanV cases belonged to this type. Spastic paraplegia was intense during one year, and was asso- ciated with ankle clonus and Babinski's sign, presenting the clinical picture of what is described by French writers as spastic dorsal tabes. Disseminated sclerosis, Erb's form of spinal syphilitic myelitis, and combined sclerosis in an early stage may present the same clinical picture. After a year pro- gressive amyotrophy of the hands was observed, then the legs became affected, and still later the bulbar muscles. Mills excludes Gowers' atonic variety in which both upper and lower limbs are the seat of wasting without spasm, except in such cases in which the lower motor segments degenerate first, especially if the degeneration be complete, as any degeneration of the upper motor segment may then fail to produce the usual symptoms. It may be said, however, that all such cases clinically belong to progressive spinal muscular atrophy or chronic poliomyelitis, and their true relation cannot be recognized without necropsy. Not only may the peripheral motor segments be alone affected, but sufficient cases are now on record to show that degeneration may be confined to the central motor segments. The most important symptoms are weakness, spasticity, fibrillary tremors, exaggerated tendon reflexes, contractures, muscular atrophy, and bulbar disturbances. The weakness is an early manifestation, and is caused 'Raymond and Cestan, Revue Neurologique, 1905, p. 504. PLATE II Amyotrophie Lateral Sclerosis. Intense atrophy of the hands. PLATE III Amyotrophi. — The first symptoms usually develop during early adult life. E. Miiller found that in 44 per cent, of his cases the earliest signs appeared during the third decade. Byrom Bramwell met with 55 per cent, com- mencing during this period, while in 85 per cent, of his cases the disease first manifested itself between the fifteenth and thirty-fifth years. It is very unusual for the disease to begin after forty years of age. Instances have been reported in which some of the symptoms appeared to date back to infancy. Schupfer,1 who in 1902 collected 59 cases reported as commencing in childhood, considers that the diagnosis was often un- warranted. Miiller has discussed the data exhaustively, and comes to the conclusion that a true multiple sclerosis in childhood identical with that occurring in the adult has yet to be demonstrated. Infections. — Kahler and Pick indicated in 1879 that insular sclerosis often develops after an acute infective disease. Pierre Marie in his Diseases of the Spinal Cord (1892) strongly advocates this view. Of 25 cases which appeared to follow upon an infective malady, typhoid fever was in 11 instances the preceding disease. The apparent onset of the first symptoms after influenza, measles, scarlet fever, diphtheria, smallpox, cholera, etc., has been observed. To account for this, Marie supposes that its cause is "the result of one of those combined infections which are so frequent during the course of the different infective diseases." It cannot be denied that an infective malady sometimes appears to act as an augmentatory cause, yet it is ex- tremely doubtful whether it alone is ever the essential factor, The writer's experience has convinced him that in a considerable proportion of these cases, in which the patient attributes his illness to one or other of these diseases, careful inquiry demonstrates that undoubted symptoms of the affection have been previously in existence. The prevalence of influenza during the last two decades has been regarded as possibly accounting for the increase in the number of cases of disseminated sclerosis met with during the same period. Advance in diagnosis offers an alternative explanation. Finally, although it is improbable that the infective diseases actually determine the incidence of disseminated sclerosis, it must be admitted that a very pro- nounced increase in the severity of the symptoms is a common sequel to these disorders. Syphilis plays no causative role in relation to disseminated sclerosis. Proof of this assertion is found in the rarity with which a history of syphilis or evidence of that disease is forthcoming (there was a history of syphilis in only 3 of the 206 cases analyzed by Frankl-Hochwart), the fact that the sexes suffer almost equally, and the circumstance that among a population in which syphilis and the parasyphilitic affections are common, there is no corresponding increase in the cases of disseminated sclerosis. The writer's experience in this connection is of some interest. In the Out-patient Depart- ment of Leith Hospital, which draws its material from a seaport town of 80,000 inhabitants, during a period of four years, he met with 62 cases of tabes as compared with 2 cases of disseminated sclerosis. Trauma. — In 1901 Gumbrecht2 collected 54 cases in which it was claimed that trauma was of etiological importance. Grossmann3 has recently 1 Monatsschr. f. Psych, u. NeuroL, Band xii, Heft 1 und 2. 2 Inaug. Diss., Leipzig. 3 Deutsche med. Wochenschr., 1905, No. 41. DISSEMINATED SCLEROSIS 145 reviewed the literature. Von Leyden, Hoffmann, and a number of other observers have recorded cases in which they regarded injury as the cause. Striimpell, Marie, and others, on the contrary, doubt whether trauma ever acts as the actual cause. E. Mendel held, and with this opinion the writer is in agreement, that injury may act as an exciting cause in an individual who is predisposed. Metallic Poisons. — Oppenheim has published observations which suggest that poisoning by lead and other metals may play a role. Among 28 cases in which the diagnosis was certain, and in which special inquiry was made into this point, in 11 a history of exposure to possible metallic poisoning by lead, copper, zinc, and other metals was obtained. The observations of subsequent writers have failed to demonstrate this relationship although Embden has described very similar symptoms in manganese workers. Hereditary Predisposition. — Eichorst and Lenot have recorded cases of disseminated sclerosis occurring at an early age, in each instance the mother of the patient having suffered from that disease. In Eichorst's case, which was examined post mortem, the pathological findings are not, however, altogether conclusive. There is no undoubted instance on record, so far as the writer knows, .in which a diagnosis of family disseminated sclerosis has been verified by autopsy. Some of the cases referred to have undoubt- edly belonged to the category of the familial spastic paraplegias. A special family tendency to nervous disease is not usually met with in this disease. Social Conditions.. — The fairly well-to-do, lower and middle classes are, in the writer's experience, at least as liable to the disease as are the lowest grades of society, if not more so. The subjects of disseminated sclerosis are indeed often healthy, well-marked girls brought up in the country. Emotion. — Mental shock, fright, worry, or grief are sometimes blamed by the patient as the cause of the symptoms, which certainly appear to be aggra- vated by psychical disturbances. The first symptoms sometimes appear after undue fatigue or exposure to cold. From what has been said it will be seen that the onset has been attributed to a variety of exogenous influences. The very multiplicity of these apparent causative factors, the circumstance that each only occurs in a small proportion of cases, and their frequency apart from the disease in question would suggest that they are most probably all of secondary importance. Pathology. — Disseminated sclerosis is characterized anatomically by placques or islets of disease scattered haphazard throughout the central nervous system. The cranial nerves are often invaded, while similar lesions have also been found in the spinal nerve roots. A classification into cerebral, spinal, and cerebrospinal types, although of clinical value, cannot in the pathological sense be strictly adhered to, since it seldom if ever happens that the patches are confined either to the brain or spinal cord. The pia mater has been sometimes described as unduly adherent. A slight degree of atrophy of the cerebral convolutions has been occasionally observed. In one or two exceptional instances, as in a case recently examined by the writer, the unusually small size of the spinal cord attracted attention. Glistening patches of variable size and shape and of a grayish color are in some cases to be seen shining through the pia mater which covers the surface of the cord, and on section these are seen to correspond with diseased placques situated in its substance. VOL. vii. — 10 146 DISEASES OF THE NERVOUS SYSTEM Upon section, islets of a gray or grayish-pink color are, as a rule, readily recognizable. It may be, however, that the diseased patches are not to be detected until the tissue has been placed in Muller's fluid or chrome alum. A slight degree of shrinking of the cord is sometimes observed in the neighborhood of patches of old standing, yet the contour of the transverse section is seldom modified in a striking manner thereby. The islets of disease are often firmer than the surrounding tissue; indeed, they may have almost the consistence of india-rubber. This fact may be demonstrated by attempting to pass a horse hair through the affected region. Sometimes the placques are distinctly softer than the normal cord. Both firm and soft patches may co-exist in the same case. The patches vary greatly in size and shape. In the brain they may be as large as a walnut; the majority, however, are very much smaller, and many are only recognizable on microscopic examination. The greater part of the transverse section of the spinal cord may be involved at one level, while a section a centimeter above or below may present an almost healthy appear- ance. A patch involving a large area may sometimes be traced through several segments. The patches may be wedge-shaped, rounded, oval, or quite irregular in contour; indeed, there is no characteristic type. It is most unusual to find a patch of any size which does not extend to the periphery of the cord. The one situation in which the writer has found a notable exception to this rule is in the posterior columns. In two cases a large oval patch extended through several segments in this region. Personal observa- tions from an examination of seven cases lend no support to Obersteiner's statement that the lumbar region of the spinal cord is less commonly involved than the parts above this level. It has been affirmed that certain parts of the transverse section are more liable to suffer than others. Thus most observers hold, and with this con- clusion the writer is inclined to agree, that the white matter is especially implicated. E. W. Taylor,1 from a study of eight cases, concludes that both gray and white matter are irrespectively involved. Ribbert asserts that the gray matter often offers a barrier to the spread of the diseased area. The writer's personal observations are in accord with those of Dejejine and E. W. Taylor, who failed to find evidence in support of this conclusion. Bourneville and Guerard regarded the long tracts, Ziegler and E. Miiller the posterior columns, as the regions of predilection. Obersteiner and others have noted a striking tendency to symmetrical affection of the spinal cord, medulla, and pons. This is, however, far from a constant feature. William- son and Rossolimo have reported cases in which the distribution of the patches corresponded to that of the bloodvessels. In not one of the seven cases examined by the writer was it possible to assert that this was so. In the brain the basal ganglia and the neighborhood of the ventricles, the corpus callosum, the pons (Striimpell), centrum ovale (Gowers), and the neighborhood of the olives are favored sites. For long it was supposed that the cerebral cortex was always spared. Oppenheim, E. W. Taylor, and Sander have shown that patches in the cortex are by no means uncommon. Islets of disease are comparatively rarely met with in the cerebellum. Weigert, however, has drawn attention to diffuse changes consisting in an increase of the tangential and radial fibers in this situation. 1 Journal of Nervous and Mental Disease, June, 1906. DISSEMINATED SCLEROSIS 147 For long it has been known that patches of sclerosis may occur in all the cranial nerves in some part of their course. The optic nerve and tract appear to be specially favorite situations. Changes in the anterior and posterior spinal nerve roots have been noted by several observers. On the other hand, it is doubtful whether the peripheral spinal nerves are ever implicated, although it must be admitted they appear to have been seldom systematically examined. Histology. — The two most striking features of the diseased areas are the disappearance of the myelin sheaths and the increase in the neuroglial tissue. The consistence of the patches varies with the degree of neuroglial prolifera- tion. Tredgold1 divides the islets of disease into three varieties, hard, soft, and intermediate. Hard islets occur chiefly in the cord, and consist of a dense interlacement of thickened neuroglial fibers with very few glia cells. Nerve fibers are practically absent, although occasionally a naked axis cylinder is met with. There are no products of degeneration and but few bloodvessels. Soft islets, which were confined to the brain in Tredgold's three cases, usually had a well-defined margin, often surrounded by a zone of leukocytes, and consisted of a loose reticulum containing a semifluid material. They are generally devoid of nerve cells or fibers, there is no neuroglial proliferation, and usually no degeneration products. The vessels are often much congested. Intermediate islets contain nerve fibers in every stage of degeneration. Products of degeneration are abundant and the neuroglia is somewhat thickened and has a finely granular structure. Glia cells are often plentiful, the vessels are distended, and their lymphatics filled with leukocytes and fat containing cells. Although the borders of the patches usually appear well defined to the naked eye, under the micro- scope a gradual transition from diseased to healthy tissue is generally recog- nizable. The changes in the myelin sheaths are well seen in the intermediate islets, particularly toward their periphery. The first alteration appears to consist in swelling of the myelin substance. This often presents a finely granular structure, and is stained faintly by coloring reagents. Later the myelin sheaths begin to disintegrate, undergoing a process of lecitholysis or fatty degeneration. At this stage the myelin sheath presents in longitudinal sec- tions a varicose or scalloped appearance. Finally, it completely disappears. The axis cylinders persist after their medullary sheaths have disappeared. This observation, first made by Charcot, is of great pathological and clinical interest. The unclothed axis cylinders do not, however, always present a healthy appearance. Some of them are swollen, many, on the other hand, are considerably reduced in diameter, and on longitudinal section are found to be fusiform in shape. Popoff, Erben, and Strahuber assert that these fine axis cylinders are newly formed, while Weigert and others believe that they are atrophic fibers. Bielschowsky, using his silver impregnation method, has demonstrated that the axis cylinder sometimes presents a knobby appearance like a string of pearls, and that it is sometimes split up into a bundle of fine fibrils. The same observer has traced the axis cylinder through a diseased patch to its continuation once more as a myelinated fiber. Kaplan, using his elective axis cylinder method, has demonstrated what he regards as a cement substance (axostrome) in the axis cylinder, with staining properties 1 Rev. of Neural, and Psychiat,, 1904. 148 DISEASES OF THE NERVOUS SYSTEM identical with the medullary sheath. Some naked axis cylinders retain their axostrome, others lose it. Secondary degenerations, although described (Babinski, Jolly, Rossolimo), are undoubtedly uncommon, as the comparative integrity of the axis cylinders within the placques might lead one to expect. Even when present they rarely extend more than a short distance from the placques which produce them. The nerve cells of the spinal cord and posterior ganglia often show a degree of chromatolysis and an increase of the intracellular pigment, but these alterations are usually surprisingly slight, even in cells situated within the more chronic patches. The neuroglia in the firmer patches consists of a dense felt-work of fibers with few nuclei. Recent patches show a more open network. According to Weigert, the neuroglial increase met with in disseminated sclerosis is denser than that in any other condition. Changes in the bloodvessels were first described by Rindfleisch. Ribbert found a large vessel situated more or less in the centre of most of the patches in those cases he examined, and in two instances he found appearances suggesting with great probability an arterial thrombosis. Dejerine and Thomas point out that the vessels may be more numerous than normal in the sclerosed areas. Thickening of the vessel walls has been described by several observers, and narrowing of the lumen with, indeed, actual occlu- sion has been recorded. Hyaline degeneration of the wall has also been noted. Notwithstanding the above-mentioned records, it is to be borne in mind that in a number of cases which have been examined no pathological changes in the bloodvessels have been met with (Taylor, Schiiler, Buchwald, Jolly, the writer), while the circumstance that these changes when present are limited to the patches, and may well be secondary to the neuroglial increase, must be kept in view. Rossolimo indicates that slight inflammatory changes are to be found in some cases in the neighborhood of the vessels. Thus the perivascular spaces are dilated and contain both mononuclear and polynuclear leukocytes in various stages of fatty degeneration. Borst, who also emphasizes these changes in the perivascular lymph, holds that a lymph stasis may be a factor of importance. Goldscheider described an acute case after typhoid fever with marked changes around the inflamed vessels. Pathogenesis. — This is most obscure. The problem involves the nature and sequence of the histological changes and their cause. In the first place, the author sides with E. Miiller, who, following Ziegler and Schmaus, speaks of a primary as opposed to a secondary disseminated sclerosis, thereby excluding such cases as those described by Williamson, Marburg, and others, in which prominent changes in the bloodvessels and the distribution of the diseased areas suggest their dependence upon interference with the vascular supply. It is obvious that the diseased process may begin either in the neuroglia or in the parenchyma, or that it may affect both tissues simul- taneously to a greater or less degree. E. Miilier is a strong supporter of the view that the initial change consists in a neuroglial proliferation, as a result of which the nerve elements are strangled. In favor of his opinion he states that the patches are especially prone to occur in regions where the neuroglia is normally most dense, and, further, that the density of the neurog- lia in disseminated sclerosis is much in excess of that met with in anv other DISSEMINATED SCLEROSIS 149 affection of the nervous system. Again, he points out that toward the edge of a placque increase in the neuroglia may sometimes be seen surrounding perfectly healthy nerve fibers. Even if we grant that the neuroglial increase is greatest in the regions in which the neuroglia is normally most dense, this is not a weighty argument in support of the primary affection of the neuroglia. Further, in cases of sharply defined secondary degeneration occurring in the spinal cord, a neuroglial proliferation which must be second- ary to the atrophy of the nerve fibers is sometimes observed beyond the limits of the degenerated tract (Mott and others). Very strong evidence against the primary neuroglial origin of the disease is afforded by the facts that in some patches very little neuroglial increase is to be observed, and that such islets may co-exist in the same case with others in which the neuroglial proliferation is excessive. Further, the rapidity with which symptoms develop and the manner in which they vary in intensity are difficult to explain on this hypothesis. Striimpell,1 who holds very similar views to Mtiller, regards the condition as a multiple gliosis predisposed to by a congenital factor, although deter- mined, it may be, by a variety of exogenous causes. His conclusions are largely based upon two cases examined post mortem, in which a multiple gliosis was associated with hydromyelia. The view, which is supported among others by Risien Russell2 and Tred- gold, that the primary change is in the parenchyma, the neuroglial increase being a compensatory process, has much more to commend it in the opinion of the writer. The strongest argument in support of this view is the cir- cumstance that very profound changes are sometimes found in the myelin sheaths, with little or no increase of the neuroglia in the same region. Toward the periphery of a patch, for instance, degenerative changes are sometimes found in nerve fibers which are lying in the midst of perfectly healthy neuroglia. A third body of observers take up the position that both the myelin sheaths and the neuroglia suffer primarily as a result of a common cause. Erb, Gowers, Rossolimo, and others regard the process asa form of chronicmyelitis. Leyden and Goldscheider and Oppenheim state that disseminated sclerosis may develop as a sequel to an acute myelitis, or an encephalitis circum- scripta. E. Miiller and E. W. Taylor, on the other hand, stoutly deny any evidence of inflammatory changes in the very considerable material at their disposal. Ribbert, E. W. Taylor, Strahuber, T. Buzzard, and others believe that some toxin of undetermined nature circulating in the blood is the agent responsible for the histological changes. Symptoms. — As the multiplicity of the lesions and their widespread distribution would lead one to expect, the symptoms met with in this disease are both numerous and varied. The clinical picture is none the less distinc- tive. A classification into three clinical types — spinal, cerebral, and cerebro- spinal — as suggested by Charcot, can only be accepted in a relative sense, for cases are seldom met with in which the symptoms are exclusively spinal, while still more rarely is a diagnosis made in the presence of purely cerebral manifestations. The circumstances, first, that the patches are scattered 1 Neurol. CentralbL, 1896, p, 961. 2 Allbutt's System of Medicine, 1899, vii, 83. 150 DISEASES OF THE NERVOUS SYSTEM indiscriminately throughout the nervous system, and secondly, that in the spinal cord the motor fibers are gathered into small compass, readily explain the frequency with which paresis or paralysis of the lower limbs is observed in the early stages. Moreover, it is to be remembered that small patches scattered through the brain substance, unless they implicate special situa- tions, may fail to afford indications of their presence. The characteristic features of the morbid process, the preservation of the axis cylinders, and the destruction of their medullary sheaths, may account for the special characters of certain symptoms, such as the optic atrophy, absence of muscular wasting, and perhaps the intention tremor. Motor Symptoms.— Weakness in the lower extremities is almost always complained of, even in the earliest stages. The paresis may be so slight that its presence is only perceptible after prolonged exercise. Thus, undue fatigue in one or both lower extremities, after a long walk, is one of the commonest early symptoms. The loss of power in the limbs, which is often asymmetrical, may be so pronounced that it is only with difficulty that the patient can walk up stairs or across the room. In advanced cases the legs are completely paralyzed. Temporary paralysis of one arm is by no means uncommon as an early symptom. A slight degree of weakness in the hands and arms is often present, yet persistent paralysis in the extremities is excep- tional unless in the terminal stages. Pronounced muscular atrophy is very rare. When this symptom is present the case may simulate amyotrophic lateral sclerosis, as in a few recorded instances. Mus<*ular hypertonicity is usually associated with the paraplegic state. The spasticity is slight in some cases ; occasionally it is so pronounced that this rather than the motor weakness is the chief cause of difficulty in locomo- tion. Sudden flexor spasms often constitute a troublesome symptom, since they interfere with sleep. In the later stages of the disease flexor contrac- tures tend to develop. A slight degree of ataxia is a common early symptom in the upper limbs. The uncertainty of the required movement is clearly to be distinguished from the intention tremor presently to be referred to. Ataxia in the lower ex- tremities may usually be demonstrated; indeed, in some cases this symptom constitutes the most striking feature of the picture, even in the earliest stages. The ataxia is, as a rule, of the cerebellar type, and hence is little increased when the eyes are closed. The gait is usually altered at a very early date, yet it is sometimes sur- prising to find no appreciable alteration even in the presence of certain evidence of pyramidal disease. A common type of progression is the spastic paretic gait, in which there is a combination of spasticity and weakness, one leg being often more affected than its fellow. The patient shuffles along, dragging his feet as if the toes were stuck to the ground. In addition to the spasticity there is often some Unsteadiness in walking, a condition, in short, of ataxic paraplegia. Sometimes, indeed, incoordination is the con- spicuous feature; the ataxia, however differs notably from that of tabes, for it is rarely increased when the eyes are closed. The stiff way in which the patient holds his head and the rhythmic tremor in head and trunk met with in the classical type is almost pathognomonic. The gait is sometimes staggering and reeling, as in cerebellar disease. Another symptom, and one which is so characteristic that Charcot included it with nystagmus and speech defect as one of the cardinal signs DISSEMINATED SCLEROSIS 151 of the disease, is the so-called intention tremor. So long as the patient is in a posture of complete muscular relaxation no tremor is to be observed; if he raises his hand with the object of carrying out some definite movement, the tremor commences. It is well brought out on attempts to write. Even when the patient is able to touch the point of the nose with the finger tip without any tremor, if the finger is kept in contact with the nose for a few seconds a rhythmical tremor of small amplitude may manifest itself. The rapidity of the tremor varies from four to six per second. The tremor may spread to other groups of muscles not directly called into action by the required movement. The intention tremor is usually most marked in the hands, but it is also seen in the lower extremities. It may be seen also in the head and neck during the act of walking. This constitutes no excep- tion to the statement that the tremor only occurs during the performance of a purposive act, for while the patient is sitting or walking, the muscles of the neck require to be constantly in a state of contraction to maintain the head in this position. Tremor of the face and jaw has occasionally been observed. Intention tremor, when present, is one of the most characteristic symptoms, yet it is often absent. Much discussion has taken place as to the origin of the tremor. Charcot was of opinion that it was due to an irregularity of conduction of the motor impulses through the sclerosed areas, a result of defective insulation of the axis cylinders or changes in them consequent upon disease of the medullary sheaths. Others hold that it is due to disease located in a particular situa- tion, and in support of their view, point out that intention tremor is absent in cases in which the disease is practically limited to the spinal cord. Sensory Symptoms. — The older writers emphasized the absence of sensory disturbances. This experience is quite contrary to that of more recent ob- servers, by whom subjective sensory symptoms, often of a fleeting character, it is true, are regarded as among the most characteristic of the early signs. Feelings of numbness, formication, deadness, tingling, and pins and needles, particularly in one or both hands or feet, are very common. A girdle sensa- tion is of comparatively frequent occurrence, while a sensation of constriction around a limb is occasionally experienced. Shooting pains, especially in the lower limbs, are sometimes complained of. Giddiness, a common symptom, may occur early, and often it occurs in paroxysms. Headache, although seldom severe, is often present. Vomiting is an occasional symptom, and may occur in association with paroxysms of headache or dizziness, or inde- pendently. A fixed pain in the back situated over the lower part of the sacrum is of frequent occurrence. Objective sensory defects of slight degree may be detected in most cases at one time or another if carefully looked for. Thus, Freund, who made a special study of 33 cases, found some definite alteration in no less than 29. All forms of sensation may be implicated. The hands and feet are most often involved, but hemianaesthesia is not uncommon. The relative degree of the sensory^ disturbances and their fleeting nature are very characteristic. Tendon-jerks and Skin Reflexes. — The knee-jerks are almost always ex- aggerated and the increase is often more marked on one side than the other. In some cases a patella clonus can be elicited. Absence of the knee-jerks has been recorded, but is undoubtedly very rare. The writer cannot recall ever having seen such a case. Thomas Buzzard regards absence of the knee-jerks in association with ankle clonus as a symptom complex which is 152 DISEASES OF THE NERVOUS SYSTEM suggestive of the disease. The activity of the tendo-Achilles jerk is almost always increased. Ankle clonus, usually bilateral, but sometimes confined to one side, is demonstrable in a considerable proportion of cases. The tendon reflexes in the upper extremities are, as a rule, abnormally active. The great value of the Babinski sign or extensor plantar reflex as an indication of disease of the corticospinal descending tract has been amply confirmed. The collected experience of recent observers shows that in disseminated sclerosis, even at the time when the earliest symptoms are complained of, the plantar reflex is almost always of the extensor type. Moreover in the writer's experience the Babinski sign is usually present in its most typical form, the slow dorsiflexion of the great toe being easily elicited from the whole plantar surface. A crossed plantar reflex may sometimes be demonstrated (Byrom Bramwell). The abdominal reflexes have recently attracted considerable attention in this malady. They are sometimes difficult to demonstrate in healthy indi- viduals. Recent observations indicate (1) their absence as specially charac- teristic of disseminated sclerosis, and (2) that they disappear early in the disease. Thus, Striimpell, who examined 185 persons free from nervous disease, noted their absence in 13.5 per cent, of these; while among 24 cases of disseminated sclerosis they were absent in 67 per cent. E. Miiller found that the reflex was only absent in 5 per cent, of individuals free from nervous disease, as compared with 62.5 per cent, in 47 cases of disseminated sclerosis. The observations of Probst and Gang corroborate these conclusions. The latter writer remarks that although the abdominal reflexes fail in many organic affections of the nervous system, they never fail with so much regu- larity as in disseminated sclerosjs. There is nothing of special importance to note with regard to the cremasteric and other superficial reflexes in this disease. Micturition and Defecation. — Disorders of micturition are ultimately present in all cases. Notwithstanding contrary statements, evidence of disturbance of the function of the bladder, often so slight as to cause little or no inconvenience to the patient, is usually forthcoming if carefully inquired for even before the more permanent symptoms of the disease are fully estab- lished. Thus in 80 per cent, of Oppenheim's cases there was some disorder of micturition. The writer obtained a history of bladder disturbance in 30 out of 34 consecutive cases in which a special inquiry was made. "Precipitate micturition," or a feeling of inability to retain the urine immedi- ately the desire to empty the bladder is felt, is the abnormality usually first experienced. Another indication of defective function which usually .jfa appears at a later date is the delay which precedes the commencement of the act. The patient may require to strain for several minutes before the urine begins to flow. When the urine commences to flow it comes in a stream of full volume, although it may be defective in force. Retention of urine, a not uncommon symptom later, is a complication which must always be regarded with anxiety on account of the liability to cystitis. Incontinence is common in advanced cases, and is usually of the remittent type, but rarely depending upon complete paralysis of the bladder wall. Like so many of the symptoms of this disease, the bladder symptoms often vary from time to time. Constipation is the rule. Some loss of control is also often seen when any tendency to looseness of the bowels exists. True incontinence of faeces is most exceptional unless in the later stages. DISSEMINATED SCLEROSIS 153 The sexual functions are at times interfered with. Impairment both of the sexual desire and power have been described, and an exaggerated sexual desire has been noted in a few cases. Defects of Vision and Optic Atrophy. — Visual defects, which are frequent and characteristic, often appear at an early date. A temporary unilateral amblyopia of sudden onset and often regarded as hysterical in origin, since it is unaccompanied by changes in the fundus oculi, may indeed be the first indication of disease. Diplopia with no visible impairment of the ocular movements, another early symptom for which the patient seeks advice, was present in 13 of 31 cases recently examined by the writer. Although the visual defects are often fleeting, a permanent diminution in central vision, associated with atrophic changes in the optic discs, is often met with. Unlike the amblyopia of tabes, this defect of sight very rarely progresses to complete blindness. A central scotoma, usually bilateral, it may be for color alone, is often to be found if carefully looked for, and when present is a valu- able aid in diagnosis. Concentric contraction of the field of vision is found in some cases. Uhtoff,1 who has studied the alterations of the visual fields in 150 cases, describes six groups of cases: (1) In one-half of all cases with anomalies of the visual fields, central scotomata, usually bilateral, often relative, with no alteration of the periphery of the field, are present. (2) In rare cases peripheral contraction of the field occurs together with scotomata. (3) In a considerable percentage of cases there is an irregular peripheral contraction of the field. (4) Isolated cases present regular concentric con- traction. This condition occurs in pure multiple sclerosis as well as in those cases which are complicated by hysteria. (5) In one case there was a ring scotoma, and in another (6) a central scotoma was present, but cleared up, and then a persistent peripheral contraction of the field appeared. Atrophic changes in the optic disk are of very great importance in diagnosis. There may be some pallor of the temporal side of the disk, an incomplete pallor of the whole papilla, so that the inner part still retains a pinkish tint, or, when the process is more advanced, the whole papilla may be uniformly pale. As T. Buzzard2 has pointed out, slight differences in the color of the 'papillae on opposite sides is often of the greatest value in determining whether the appearance is to be regarded as pathological. The frequency of recog- nizable pallor of the disk has been variously estimated by different authors. Uhtoff found that the papillae presented a pathological degree of pallor in 37 per cent, of all cases, and other observers have found an even higher percentage. The dependence of the changes in the optic disks upon an islet of disease situated in the optic disks has been repeatedly demonstrated. A small number of cases have been observed in which there was a slight degree of optic neuritis, never amounting to a true papillitis. The appear- ances, which are those of a retrobulbar neuritis, have been proved to be due to the presence of a placque in the immediate vicinity of the papilla. Ocular Muscles, Nystagmus, Pupils, etc. — The ocular muscles are particu- larly liable to be affected (Uhtoff, 20 per cent.). Diplopia is often complained of. Usually when this symptom is present the paresis is so slight in degree as to escape detection unless specially examined for by the appropriate visual tests. The sixth nerve is most commonly affected, and paresis of the 1 The Ophthalmoscope, 1905, p. 429. 2 British Medical Journal, 1893, ii, 779. 154 DISEASES OF THE NERVOUS SYSTEM third is usually partial. These muscular defects are almost always of slight degree. Complete ophthalmoplegia has, however, been recorded. Ptosis either confined to one side or bilateral is of more frequent occurrence than any other form of ocular palsy. Wildbrand and Sanger lay stress on this symptom, believing that in certain cases it may be of even greater diagnostic importance than nystagmoid movements. Miiller, who met with ptosis in 8 per cent, of his cases, also observed paresis of lateral conjugate movement in three cases, of upward movement in two. Nystagmus belongs to the symptomatic triad formulated by Charcot. Three degrees may be conveniently recognized: (1) Nystagmus which occurs while the eyes are in a position of rest; (2) nystagmus which is only present in association with a fixed purposive movement such as lateral or vertical deviation or upon fixing a near object; and (3) movements which occur during fixation, but which rapidly cease and are at the same time frequently irregular both in time and amplitude. To this last group we would reserve the term nystagmoid movements. In few cases of dissemi- nated sclerosis do we find the type which we have classed in the first group. On the other hand, the second and third types are very common. The move- ments are usually fairly rapid and regular, but vary considerably in ampli- tude in different cases. Coarse nystagmus, for example, may be elicited when the patient looks to one side, while when he looks in the opposite direction the movements may be much finer in quality. The nystagmus is usually most obvious when the patient looks to the extreme left or right and at the same time directs the eyes slightly upward ; sometimes, however, when he looks directly upward or downward the movements are also visible. Occasionally the movements are only to be seen when the eyes are fixed at the extreme of the vertical plane. The direction of the oscillation is commonly from side to side, the two eyes acting in unison. A certain amount of rota- tion of the eyeball is, however, by no means uncommon, and in rare cases the oscillations take place in a vertical direction. The writer has seen one case in which the movements were confined to one eye. Kunn has noted a "Zitterbewegung" in the ciliary muscle. The writer has also observed evidence of rhythmic contractions in this muscle on- ophthalmoscopic examination. Alterations in the size and activity of the pupil are not uncommon. There was a difference in the size of the pupils in 24 per cent, of Uh toff's cases. Parinaud remarks that inequality of the pupils occurs early in the disease, and that miosis when present is spastic as opposed to the paralytic miosis of tabes. The pupils react well on convergence provided that the movement of convergence is not itself defective. The light reflex, although sometimes sluggish, is very rarely lost. Miiller notes that among 364 cases observed by Frankl-Hochwart, Probst and Uhtoff, the Argyll-Robertson pupil was only present in 4. Frankl-Hochwart mefwith hippus in 12 cases. Speech and Articulation. — In the older description of this disease speech affections occupy a prominent position. They are, however, by no means of constant occurrence. Byrom Bramwell found some defect of speech in 62 per cent, of his series, while some alteration was present in two-fifths of Miiller's cases. Among 33 consecutive cases recently examined by the writer, in 15 (45 per cent.) speech was altered. It may be that the patient notices some slight difficulty in speech, especially toward the end of a sentence, even before any change can be detected by DISSEMINATED SCLEROSIS 155 the observer. The alteration in speech in the early stages of the disease may be so slight that it is difficult to describe, and yet it may be sufficiently characteristic to the experienced observer to help him greatly in making his diagnosis. The slow and measured way in which the patient enunciates and a singular monotony of voice are usually the salient features to attract attention. When he reads aloud it is interesting to note the way in which he tries to vary the pitch of his voice, of the monotony of which he is obviously conscious. At a later date he chops his words, each syllable is pronounced slowly, hesitatingly, distinctly, and precisely. This is the syllabic, scanning, or staccato speech which has been compared by Charcot to that of incipient intoxication, by Oppenheim to that of a child learning to spell, and by Marie to that of an individual who is steadily but surely ascending a hill. Each syllable is produced with apparent effort, an im- pression which the associated tremor often present in the face and head tends to accentuate. Occasionally a nasal twang is noticeable. Miiller found a true staccato speech in only 15 per cent, of his cases. Certain letters, notably 1, p, g, b, and d, are especially apt to give rise to difficulty in pronunciation. Later in the course of the disease, defective articulation may render speech quite unintelligible. As Oppenheim observes, when an attempt is made to intone the letter e, a distinct tremor in the voice is often noticeable. This observer has drawn attention to the scanning character of the respiration, to which he is inclined to attribute the corresponding peculiarity in speech. Goldscheider believes that the monotonous character of the speech may be due to defective control over the act of expiration, for he has shown that the augmentations and interruptions in the expiratory blast, which he has demonstrated take place during the act of speaking, are in this disease abnormally slow and defective. Aphonia is occasionally present. R&hi has recently (1907) given a detailed description of the appearances in 44 collected cases in which the larynx was examined. In 63 per cent, some form of laryngeal paralysis was present, while in half the cases tremor of the vocal cords was observed. Mental Symptoms. — It is somewhat surprising to find that profound psychic alterations are exceptional. Even in fully developed cases there may be no obvious mental disturbance. As a rule, however, after the disease has been in progress for any length of time, a certain degree of mental impairment is noticeable. Thus in Byrom Bramwell's series of cases defective memory was present in 50 per cent., some emotional alteration in 40 per cent., and further evidence of intellectual impairment in 27 per cent., while E. Miiller found a slight enfeeblement of the psychical faculties in about 25 per cent. The psychic alteration shows itself especially in enfeeblement of memory, in a certain slowness of thought, in the apathy and indifference with which the patient regards his surroundings, and in a degree of stupidity which the facial expression would almost lead one to expect. A sense of well-being, or euphoria akin to the spes phthisica, is often ob- served, less commonly a depression of spirits which has been known to pass into actual melancholia. Emotional control is often impaired. The occur- rence of outbreaks of emotion does not necessarily imply a corresponding defect in the intellectual capacity. Seiffer1 has recently studied elaborately the mental state in 10 consecutive 1 Arch. f. Psych., Band xl, Heft 1, p. 252. 156 DISEASES OF THE NERVOUS SYSTEM cases. He found that 9 of these showed considerable disorder of intellect. Concrete ideas derived from the remote and recent past and the association of ideas he found to be especially defective. Attention and the grasp of abstract ideas were frequently but not so constantly impaired. He concludes that this condition of dementia is indistinguishable from that which is associated with epilepsy and alcoholism. Delusions of persecution, maniacal states, ideas of grandeur and exaltation have been observed in occasional instances. In this connection it is interesting to note that several cases have been reported in which a pathological examination established the co-existence of general paralysis of the insane.1 Trophic and Vasomotor Changes. — These are extremely rare and of corre- sponding minor significance. James Collier has reported five cases in which he noted the presence of erythromelalgia. There are a number of cases on record in which muscular atrophy was present, although this is altogether exceptional. Bedsores may develop in the terminal phases. Congestive and Epileptic Attacks. — Attacks similar in character to the congestive attacks of general paralysis of the insane have been recorded. Their rarity may be gathered from the fact that the writer, who has examined over 150 cases of this disease, can only recall one instance. Frankl-Hochwart met with apoplectic attacks in 10 of his series. The attacks have been some- times preceded by giddiness, the patient falls to the ground, is sometimes con- vulsed, and may remain comatose for several hours. The temperature is raised. Hemiplegia is an occasional sequel. Sudden attacks of giddiness and faintness without loss of consciousness are less uncommon. M tiller has met with two cases in which Jacksonian attacks occurred. Epileptic attacks were noted in 3 of Frankl-Hochwart's 206 cases. Earliest Symptoms. — Motor weakness in the limbs, and especially in both lower extremities, parsesthesias in the limbs, giddiness, tremor, or ataxia and amblyopia are, in the order stated, the most common early symptoms. The development of the initial symptoms as complained of by the patient has been studied by Byrom Bramwell (110 cases), who states: "In 41 cases the initial symptoms occurred in the extremities, and were purely motor or ataxic; in 3 cases the symptoms were purely sensory ; in 22 cases the symptoms were both sensory and motor; in 24 cases the symptoms were purely cerebral or ocular; in 17 cases there were different combinations of motor and sensory symptoms with cerebral or ocular symptoms." Ashley W. Mackintosh, who has tabulated 80 cases, for the most part drawn from Ferrier's material, remarks on the extraordinary variability of the modes of onset, the com- paratively large number of cases with acute or sudden onset (10 cases), the frequent occurrence of purely unilateral symptoms at the onset (15 cases), and the comparative frequency of the occurrence of sensory symptoms at the onset, either alone (10 cases) or combined with other symptoms (19 cases). Types. — A number of clinical types are recognizable according to the preponderance of certain symptoms. 1. The classical type, characterized by intention tremor, nystagmus, speech affection, and it may be other cerebral manifestations in association with a spastic or ataxic paraplegia. 2. A cerebrospinal type, in which even in the absence of the symptomatic 1 Hunt, American Journal of the Medical Sciences, 1903, cxxvi, 126. DISSEMINATED SCLEROSIS 157 triad of Charcot, symptoms alike cerebral and spinal point to widespread disease of the central nervous system. 3. The hysterical or intermittent type, in which fleeting symptoms sugges- tive of hysteria constitute the most striking feature of the case. 4. The spinal type, characterized by prominent spinal symptoms resemb- ling a variety of spinal diseases. Of these, a progressive paraplegia un- accompanied by sensory disturbance and indistinguishable at first, it may be, from primary lateral sclerosis is very common. Again, a spastic para- plegia may develop with the rapidity of an acute myelitis. The co-existence of ataxia and paraplegia may constitute a symptom complex which closely resembles the combined systemic diseases. 5. The cerebral type is much less common. Occasionally vomiting, giddiness, and headache are the most striking symptoms. In rare cases, a cerebral hemiplegia is met with as the leading feature of the case. Very exceptionally, bulbar manifestations or mental symptoms are the most conspicuous alterations. 6. A sacral type, recently described by Oppenheim and Kurt Mendel, in which pains in the legs, disturbance of the sphincters and sexual functions, point to a lesion in the lower part of the spinal cord. Diagnosis. — This is not so difficult as the irregular distribution of the pathological lesions and the multiplicity of types described might lead one to expect. The diagnosis is based upon (1) the detection of certain characteristic symptoms or association of symptoms, upon which alone a positive opinion may sometimes be advanced; (2) a history of variation in the severity of the symptoms, which, when present, is in itself so suggestive as to be almost pathognomonic; and (3) the exclusion of a variety of diseases, which may closely simulate disseminated sclerosis. The classical type pre- sents features which are distinctive, for intention tremor, scanning speech, and nystagmus in association with a spastic or ataxic paraplegia and an ex- tensor response place the problem beyond all doubt. These cases, however, form only a small percentage. It is especially in the early stages that errors are made, notably when temporary manifestations disappear, leaving the patient in perfect health, or when the symptoms are such that the supposition of a single focus of disease appears to satisfactorily explain them. Weakness in the lower extremities, it matters not how slight, in a young adult, if accompanied by exaggerated tendon-jerks and the Babinski sign, should always arouse in the mind of the physician the possibility of this disease, when on further examination no evidence of vertebral disease, no muscular wasting, and no objective sensory disturbances are detected. If in addition a degree of ataxia is present and the abdominal reflexes are absent, the suspicion is considerably strengthened. Further, if there is a history of previous temporary paresis or parsesthesia in a limb or of a fleeting amblyopia or diplopia, the suspicion amounts almost to a certainty. A slight degree of ataxia in the upper extremities, the occurrence of vertigo, and, above all, pathological pallor of one or both optic disks in conjunction with a spastic or ataxic paraplegia render the diagnosis almost certain, even in the absence of a history of variations in the clinical picture of nystagmus, intention tremor, or characteristic alterations in speech. Hysteria. — Of the many diseases for which disseminated sclerosis may be mistaken, this takes the first place. Disseminated sclerosis often occurs 158 DISEASES OF THE NERVOUS SYSTEM in young women, its early symptoms are often transient and completely recovered from, while hysterical stigmata are often met with in association with the organic affection. To Thomas Buzzard especially is due the credit of showing the frequency with which disseminated sclerosis is mistaken for hysteria, an error which is fortunately becoming every day less common. Transitory paresis or parsesthesia in a limb, even though completely recovered from, symptoms which some years ago would have been diagnosed as cer- tainly functional, are to be regarded with the gravest suspicion, since they are so often the precursors of the affection which we are considering. Even although a hemiansesthesia with involvement of the special senses is detected, the observer must remember that the recognition of hysteria does not exclude associated organic disease. Nystagmus, pallor of the optic disks, and the Babinski sign justify a positive diagnosis of organic disease, while incon- tinence of urine, a symptom which it is true does not usually occur until the later stages of the disease, carries with it the same significance. Acute disseminated myelitis or encephalomyelitis presents a very similar picture; some believe that it is a more intense degree of the same process. The symptoms develop acutely, it may be with fever, and reach their height in a few days. There is muscular wasting. Variations in the intensity of the symptoms do not occur. Progress is in the direction of improvement, although this is very often limited. Subacute combined degeneration of the spinal cord may simulate dissemi- nated sclerosis very closely. The diagnosis is very important, for these cases often run a very rapid course. In both diseases ataxic paraplegia is often the most striking feature of the clinical picture. Subacute combined degen- eration usually develops rather later in life, and its symptoms once present show no tendency to disappear, as in disseminated sclerosis. Pallor of the optic discs is not met with, while pronounced anaesthesia, beginning in the feet and progressing steadily upwards, is the rule. The symptom complex of the later stages, viz., the flaccid palsy, often suddenly developed, with abolition of the tendon jerks and complete loss of control over the sphincters, places the diagnosis beyond all doubt. Cerebrospinal syphilis occasionally closely resembles disseminated sclerosis. The peculiar pallor of the optic disks, the presence of a color scotoma, and absence of the abdominal reflexes speak strongly for disseminated sclerosis. Scanning speech and intention tremor do not occur in cerebrospinal syphilis. The Argyll-Robertson pupil is almost conclusive evidence of syphilis of the nervous system, corroborative evidence of which is afforded by the detection of a cerebrospinal lymphocytosis or a positive Wassermann reaction. Im- provement under antisyphilitic remedies may confirm the diagnosis. General paralysis oftheinsane has been known to cause trouble in diagnosis. The writer has met with one instance in which this was so. The more pro- found mental alterations, a history of syphilis, and the existence of the Argyll- Robertson pupil, a cerebrospinal lymphocytosis or positive Wassermann reaction are data of importance. Cases have been recorded in which the lesions of disseminated sclerosis and general paralysis of the insane co-existed post mortem. Intracranial tumor is a diagnosis sometimes made in the early stages of disseminated sclerosis. The writer has seen this error made on three occa- sions by eminent authorities, the subsequent progress of the case demon- strating its true nature. Giddiness with vomiting, unsteady gait, nystagmus, DISSEMINATED SCLEROSIS 159 and tremor may all result from a patch of sclerosis situated in the cerebellar peduncles. Headache may be present, though rarely severe, while in very exceptional cases there may be a slight degree of optic neuritis. All forms of spastic paraplegia in which the paralysis of the lower limbs is the dominant feature may cause difficulty. Many of the cases formerly classed as primary lateral sclerosis, an affection which we now know to be one of the rarest of organic nervous diseases, were without doubt examples of disseminated sclerosis. It may be, indeed, that there is at the present time a tendency for the pendulum to swing too far in the opposite direction. The possibility of amyotrophic lateral sclerosis must always be kept in view. The differential diagnosis from pseudo-sclerosis and diffuse sclerosis will be considered under these diseases. Prognosis. — It is very doubtful whether permanent recovery ever takes place. Cases have been observed in which the patient has remained free from symptoms for several years. Thus, Oppenheim mentions three examples in which the patients had recovered and been in perfect health for from five to ten years, and similar instances have been met with by others. No less uncommon, however, are cases such as those recently reported by T. Buzzard in which after intervals of several years the symptoms of the disease have reappeared. Time may show that very exceptionally per- manent recovery may take place. For the present this question cannot be answered in the affirmative. The disease tends in the majority of cases to run a chronic course, often interrupted, it is true, by remissions and relapses. There are instances in which death has occurred within a year, but these are exceptional. Byrom Bramwell has ascertained the duration of life from the appearance of the first symptom in the 35 fatal cases of his series. He found that in 10 cases (28.5 per cent.) death occurred in less than five years, in 23 (65.7 per cent.) in less than ten years, and in 31 (88.5 per cent.) in less than fifteen years ; one patient died within a year. In no instance was the duration more than twenty-one years. On the other hand, among 61 non-fatal cases, 5 had lived at the time of writing for various periods from twenty-two to thirty-three years. The average duration of life in 96 fatal and non-fatal cases was found to be ten and a half years. There are practically no available data which permit of an opinion as to the probable course or duration of a particular type of case when seen in its early stages, although if bulbar symptoms or pronounced bladder trouble appear early the expectation of life will probably be less than the average. Treatment. — Conclusions as to the beneficial effect of this or that line of treatment are naturally extremely difficult to arrive at in the case of an affec- tion such as disseminated sclerosis, in which there is a tendency for inter- missions and remissions to occur quite independently of all therapeutic- intervention. No known remedy has been proved beyond doubt to exert a favorable effect, hence in our present ignorance as to its pathology, treatment is limited (1) to certain general directions indicated by common-sense; (2) to the avoidance of circumstances which may be expected or have actually been proved to have a deleterious influence; and (3) to attempts to alleviate indi- vidual symptoms as they arise. The spirit of optimism which these patients not uncommonly present should, so far as possible, be left undisturbed by the physician, for even 160 DISEASES OF THE NERVOUS SYSTEM although it is perhaps unreasonable to suppose that such a mental state can influence the course favorably, yet it is certain that prospects of improve- ment do much to make the patient's outlook on life more bearable. Strict injunctions are to be laid down as to the avoidance of muscular exhaustion and in particular the patient should be cautioned when walking always to stop short of fatigue. Confinement to bed is, on the other hand, a mistake; indeed, the patient should rather be encouraged to regularly exercise his muscles. A warm climate may be recommended to those who can afford it. Plenty of fresh air and a nutritious diet are advisable. Worries of all kinds are to be, as far as possible, avoided. Hot baths are contra- indicated, experience having shown that sometimes harm is done thereby. Marriage should be forbidden. The prejudicial effect of pregnancy is undoubted and should be explained to female patients. The induction of abortion may be even justifiable, especially when it is ascertained that during a previous pregnancy the symptoms were intensified. Ataxia when pronounced is at times benefited by a course of coordinated exercises, although the brilliant results sometimes obtained by this method in the treatment of tabes are not to be expected. No drug is known which influences the intention tremor. Flexor spasms, often a troublesome symp- tom, since they interfere with sleep, are occasionally alleviated by five to ten grains of veronal given at night. When rigidity of the limbs is extreme the cautery applied to the back on either side of the spine may prove of service. Incontinence of urine, if due to overflow from a distended bladder, is to be treated by the passage of the catheter at regular intervals, while if it is of the intermittent variety, benefit may result from tincture of belladonna in 10 minim doses. Obstinate constipation is best relieved by a daily soap and water enema. In bedridden cases a water bed is indicated. Bedsores are to be avoided by thorough attention to cleanliness; the skin is to be washed with alcohol twice a day and the parts dusted with some bland non-irritating powder. Associated hysterical symptoms should be treated by a confident predic- tion that they will disappear and by the methods of suggestion and persua- sion commonly employed in the treatment of such manifestations. Although no drug has been definitely proved to have any effect upon the course of the disease, the writer is inclined to believe that arsenic in moderate doses, 2 to 6 minims of the liquor three times a day, is sometimes of service. Strychnine is to be avoided, since it tends to increase the spastic state. Pseudo-sclerosis. — Historical. — Westphal described under this name two cases, diagnosed during life as disseminated sclerosis, in one of which the autopsy was entirely negative, while in the other the only change found was a general increase in the consistency of the brain. Striimpell gave the first distinctive description of the symptom complex. Frankl-Hochwart1 has studied the cases reported up to 1903, 13 in number. Two important contributions have since appeared, one by Fickler2 who has reported two cases and has reviewed the literature up to date. The other is by Rebizzi,3 who regards pseudo-sclerosis and diffuse sclerosis as the early and late stage of the same affection, for which he proposes the inclusive title of Westphal- Strumpell's disease. 1 Arb. aus dem Neurol. Institut an der Wiener Universitat, 1903, Heft 10, p. 1. 2 Deutsche med. Wochenschr., 1904, No. 51. 3 Riv. di patol. nerv. a ment., vol. x. PSEUDO-SCLEROSIS 161 Etiology. — Baumlin's four patients were sisters, and Rebizzi has described cases occurring in father and daughter. A strong neuropathic heredity has been a striking feature in several instances. In no case has there been any definite relationship to trauma. Males and females are equally affected. The symptoms developed in 5 cases during the first decade, in 3 during the second, in 1 during the third, and in 4 during the fourth. Pathology. — No changes were found post mortem in the majority of the cases examined. It should be mentioned, however, that in 6 cases a micro- scopic examination of the brain was not made, and that the majority of the observations predated the introduction of elective staining methods. The consistence of two of the brains examined is described as abnormally dense. A spinal leptomeningitis, slight in degree, was found by Baumlin in one case. Striimpell met with a very slight degeneration in the cervical portion of the pyramidal tracts in both his cases, in one of which similar changes were also observed in the cervical portion of Gowers' tracts. The disease has been regarded by Marie and other French writers as a neurosis; the changes above described are, however, apart from any clinical considerations, quite sufficient to negative this view. Rebizzi and Frankl- Hochwart remark that the morbid anatomy of pseudo-sclerosis cannot be strictly separated from that of diffuse sclerosis, for cases are on record which might be included in either group, the two conditions merging into one another. Symptoms. — Mental changes are the rule. A degree of apathy, peculiari- ties of disposition, irritability, and attacks of temper are among the altera- tions noted, while maniacal outbursts with hallucinations have been reported. Epileptic attacks were present in 6 of the 13 cases collected by Frankl- Hochwart. Some disorder of speech was observed in 9 cases, in 5 of which speech was described as scanning, while in 2 it was unintelligible. Facial paralysis has not been noted, although in 3 cases a defect in facial mimicry was remarked on. The optic disks were normal in every case, with the exception of one instance reported by Fickler. The special senses have always been normal, as were the pupils. Nystagmus was present in one case only, and once paralysis of the oculomotor nerve was observed. Dysphagia was present in one case. Giddiness was complained of in three cases, while headache, faints, apoplectiform attacks, and uncontrollable outbursts of laughter were each noted on two occasions. Weakness of the extremities is described in two-thirds of the reported cases. Three times the paresis was hemiplegic in distribution; in one case all four extremities were involved. The gait is referred to as "clumsy, ataxic, or unsteady" in 5 cases, twice it is noted as spastic, and in two instances the patient was unable to walk. Tremor in the upper extremities was a constant symptom. In four cases it occurred during repose. It was of larger ampli- tude and less regular than in disseminated sclerosis. Three times the lower limbs were also affected, the head was implicated in 3 cases, while twice the face and tongue were also involved. Contractures, sometimes tempo- rary, sometimes permanent, were present in 9 cases. In 3 cases the neck muscles were affected, in 6 the arm, and in 7 the legs. Pains, sometimes rather intense, were occasionally complained of. Three patients suffered from parsesthesias of various kinds. In one of Westphal's cases hypersesthesia in different situations was noted at times in association with some loss of sense of position. VOL, vn. — 11 162 DISEASES OF THE NERVOUS SYSTEM The tendon reflexes, examined in 10 cases, were once found to be normal, while on nine occasions they were exaggerated, clonus being present in five. In Fickler's case the superficial reflexes were absent, otherwise no anomalies of the skin reflexes have been met with. In 2 cases there was inconti- nence of urine, while in 1 there was incontinence of faeces. Transitory vasomotor disturbances were occasionally noted, and in 3 cases bedsores developed toward the termination. In 3 cases death occurred in from nine to ten -years, in 3 from four to six years, and in 4 from one to two years. Frankl-Hochwart's patient lived for fifty-seven years after the onset of symptoms. Pronounced inter- missions similar to those met with in disseminated sclerosis were present in three cases, while in the records of several others there are indications of the same. Diagnosis. — Pseudo-sclerosis bears a very close resemblance clinically to disseminated sclerosis, from which it has rarely been distinguished during life. The chief points of importance which distinguish pseudo-sclerosis are the frequency of mental changes, notably attacks of excitement and pro- nounced dementia; -the wild character of the tremor, which sometimes occurs during rest, a very rare occurrence in disseminated sclerosis; the occurrence of epileptic attacks, which were present in half the recorded cases of pseudo-sclerosis, but is very rare in disseminated sclerosis; the absence of changes in the optic disks; the comparative insignificance of the paretic symptoms in the lower limbs until the later stages, and the relative rarity of bladder symptoms. The development of the earliest symptoms during the first decade would be a strong point in favor of pseudo-sclerosis, as would a history of a similar malady affecting a relative. The diagnosis from diffuse sclerosis we shall consider under that affection. Diffuse Sclerosis. — This rare affection, like pseudo-sclerosis, bears a close resemblance clinically to disseminated sclerosis. Etiology. — It commences not uncommonly in childhood, sometimes not until the third or fourth decade. Unlike pseudo-sclerosis, heredity does not appear to be of etiological importance. On the other hand, there is a history of associated trauma in about a third of the reported cases. A relationship with alcohol, meningitis, and syphilis has been claimed in indi- vidual cases. Pathology. — The most striking feature is the dense consistence of the brain, which has been described by individual writers as leathery, like india- rubber, elastic, and cutting like cartilage. The cut section looks almost like ivory. Weiss points out that where there is much shrinking, hydrocephalus internus and externus with ventricular dilatation may result. The altera- tion in consistence is associated with a great neuroglial increase throughout the nervous system, the neuroglia fibers forming a dense feltwork with numer- ous nuclei. The vessels are not greatly increased in number, although their walls are thickened. As already mentioned, the changes in some of the reported cases of pseudo-sclerosis are so similar to those met with in diffuse sclerosis that Rebizzi regards the two affections as merely the early and late stages of the same disease. Symptoms. — These are so similar to those of pseudo-sclerosis that it will be unnecessary to do more than indicate the main resemblances and differ- ences. In both the mental alterations occupy a prominent place, though in diffuse sclerosis dementia is more common and more profound. Speech MILIARY SCLEROSIS 163 disturbances occur in a large proportion of cases of diffuse sclerosis, and are also more marked than in pseudo-sclerosis. Tremor occurs in about two- thirds of the cases while paresis in the lower limbs with an unsteady gait are about as common as in pseudo-sclerosis, although, as a rule, more pronounced in degree. Aphasia, present in a third of the reported cases, is unknown in pseudo-sclerosis. Facial paresis has been described in a number of instances, and dysphagia, a symptom only once observed in pseudo-sclerosis, was pres- ent in half the reported cases. Giddiness and epileptic attacks occur about as frequently in the two conditions. Muscular atrophy has been described in a few cases of diffuse sclerosis, never in pseudo-sclerosis. Objective disturbances of sensation are much more frequent in diffuse sclerosis, occur- ring in almost half the cases; incontinence of urine and of faeces are also of frequent occurrence. The average duration of life is from one to three or four years, and the course is steadily progressive. Diagnosis. — The distinctive features from disseminated sclerosis are almost identical with those laid down in considering the differential diagnosis of pseudo-sclerosis from that disease. Pseudo-sclerosis may, in certain in- stances, possibly be distinguished clinically from diffuse sclerosis, but it must be remembered that cases are met with in which one disease runs into the other. Tuberose or Hypertrophic Sclerosis. — Bourneville1 described in 1880, under the title "Sclerose tubereuse des circonvolutions ce're'brales," a condition characterized by overgrowth of the neuroglia in circumscribed islets which project from the surface of the cortex cerebri and from the walls of the lateral ventricles. Peculiar subcapsular tumors of the kidney are also met with. The disease is probably dependent upon a developmental anomaly. Sailer2 has collected 28 cases. A. W. Campbell3 has analyzed 20 cases, and found that in no less than seventeen there was idiocy or imbecility, and that congenital mental weakness could not be excluded even in the remaining three. This author refers to the constant occurrence of adenoma sebaceum, a congenital affection of the skin, affecting especially the region of the nose and the naso-labial folds. The occurrence of adenoma seba- ceum in a young patient suffering from amentia and epileptic attacks would probably justify a diagnosis. Miliary Sclerosis. — Under this name Gowers4 described a case in which "throughout both hemispheres of the brain, and in all parts of them, the cortex contained minute reddish-gray spots at the junction of the gray and white substance." There was wasting of the nerve elements and an increase in the connective tissue in the affected areas. The patient was a man, aged fifty years; the chief symptom was general weakness of the limbs, with some rigidity and a few unilateral convulsive attacks. The speech became mumbling and unintelligible, and the patient became comatose and died. There was a history of syphilis. The total duration of the symptoms was about ten weeks. Greiff has described similar appearances in general paralysis of the insane. 1 Archiv. de N enrol., 1880, i, 91. 2 Journal of Nervous and Mental Disease, 1898, xxv, p. 402. 3 Brain, 1905, xxviii, p. 382. 4 Lancet, 1886, i, 145. CHAPTER V. THE DISEASES OF THE MENINGES. BY EDWIN BRAMWELL, M.B., F.R.C.P. (LOND. and EDIN.). Anatomical and Physiological Considerations.— The central nervous system is invested by three membranes : the dura mater, the arachnoid mater, and the pia mater. The dura mater, a dense fibrous tissue membrane, divisible into two layers and lined on its inner surface by endothelium, lies in close contact with the inner table of the skull and is continued as a fibrous sheath on to the cranial nerves. Three prolongations of the dura mater, the falx cerebri, tentorium cerebelli, and falx cerebelli, extend into the cranial cavity and play an impor- tant role as supporting structures. The dura mater is for the most part irrigated by the middle meningeal artery, while the trigeminus is its source of nerve supply. The arachnoid mater and pia mater, the leptomeninges, are commonly described as the "pia arachnoid," since diseased processes which affect the one always involve the other. The pia mater is a thin vascular layer of fibrous tissue, which lies in the closest contact with the outer surface of the central nervous system. A prolongation of the pia mater, the velum inter- positum, passes into the transverse fissure of the brain, carrying with it the choroid plexuses. The arachnoid, on the other hand, is a non-vascular fibrous tissue membrane. It lies external to the pia mater, with which it is connected by a delicate meshwork of fibrous tissue strands, and it is covered on its outer surface by a layer of endothelium. The arachnoid does not dip into the sulci as does the pia, but bridges them over. The inner surface of the ventricles is lined by a layer of endothelium known as the ependyma. The subarachnoid space which lies between the pia and arachnoid contains the cerebrospinal fluid. Its meshes communicate freely with one another. The two membranes are widely separated where they lie between the cere- bellum and medulla, and the space so formed is sometimes known as the posterior subarachnoid space or reservoir. The foramen of Magendie and the two adjacent foramina of Luschka offer the only means of communication between the subarachnoid space and the intraventricular system. The cerebrospinal fluid is a perfectly clear fluid with a slight alkaline reaction and a specific gravity of 1006. Its principal constituent is sodium chloride. Traces of carbonates and phosphates are also present. It con- tains traces of globulin and of urea, also a Fehling reducing substance which is probably glucose. With the exception of a few lymphocytes it is devoid of cellular elements. Although it is held by some that the cerebrospinal fluid is a transudation, the researches of Halliburton as to its chemical composition afford strong evidence for believing that it is not an exudation, but a true secretion. The fluid is in all probability secreted by the epen- (164) P ACHY MENINGITIS 165 dymal cells, which cover the choroid plexuses, and the secretion is probably a continuous process. The amount produced in the twenty-four hours has been variously estimated, some observers placing the quantity as high as one or two liters. Observations upon this point are possible when after certain cerebral operations the cerebrospinal fluid which escapes from the wound can be collected. It is, however, somewhat doubtful whether these results can be regarded as a true estimate of the normal secretion, since the operative procedure and the pathological condition for which it has been undertaken may alter its amount (Gushing). The fluid fills the whole intraventricular system, and through the foramina of Magendie and Luschka has free access to the cerebrospinal subarachnoid space. Since the secretion of fluid is in all probability a continuous process, it follows that in order to regulate the intra- cranial pressure there must be a constant return of the fluid into the blood stream. This may take place by the lymphatics of the outgoing cranial and spinal nerves, the fluid passing by way of the thoracic duct into the venous circulation. Key and Retzius believed that Pacchioman bodies act as filters through which the fluid finds a path of egress. Gushing doubts this, since these structures do not exist in the lower animals or in young people. The last named observer believes with Leonard Hill that the fluid passes directly through the walls of the superior longitudinal sinus. Ford Robert- son has demonstrated a network of large capillaries immediately subjacent to the surface endothelium of the dura, which capillaries are surrounded by spaces regarded by him as lymph channels. He believes that the cerebro- spinal fluid may escape into these spaces, which he terms the perivascular canals of the dura, and thence into the veins of the skull. DISEASES OF THE DURA MATER. PACHYMENINGITIS. The diseases of the dura mater are naturally divisible into two groups, according to the situation of the disease, whether on the outer or inner surface of this membrane. Pachymeningitis Externa. — Inflammation of the outer surface of the dura mater is uncommon. It occurs almost always as a secondary conse- quence of neighboring disease. A cerebral and a spinal form are described. Cerebral. — The outer surface of the cerebral dura mater lies in close contact with the inner table of the skull, hence external pachymeningitis in this situation is always localized. It may be a sequel to fracture of the skull with extravasation of blood on the outer surface of the dura, erysipelas of the scalp, syphilitic caries, or tumors of the cranium. The extension of an inflammatory process arising in the labyrinth or mastoid cells may result in a localized external pachymeningitis or an extradural abscess. The clinical features are usually overshadowed by those of the primary affection, to which it owes its origin. Spinal. — The dura mater which surrounds the spinal cord does not lie in contact with the bony canal, but is separated from it by a space, which is occupied by loose areolar tissue. Hence pachymeningitis externa spinalis 166 DISEASES OF THE NERVOUS SYSTEM may be either widespread or localized. In the great majority of cases the process is secondary to disease of adjacent structures. Gowers recognizes a primary form; he says: ;rays. The most minute changes in sensibility should be noted, espe- cially in case of tumor of the dorsal region, and when a segmental area shows well-marked anaesthesia it should be concluded that at least one spinal segment above that by which the area is innervated is, in all probability, severely damaged. Thus, if definite anaesthesia can be traced as high as the seventh dorsal segmental area, the sixth dorsal segment is compressed, and the removal of the fourth and fifth dorsal laminae will expose the seat of disease. The highest indication of any disturbance of function is nearly always the safest guide to follow. The downward extent of the lesion is generally impossible to estimate. 3. It is hardly ever possible even to hazard a guess as to the histological characters of a primary intravertebral tumor until it has been exposed. It is therefore unwise to allow the question of its nature to influence in any way the consideration of treatment. On the other hand, a vertebral tumor, primary or secondary, or a secondary intravertebral growth, usually presents evidences or associations pointing to its nature. In the great majority of cases, unfortunately, the knowledge thus acquired contra-indicates the hope of a radical cure. The diagnosis between extra- and intramedullary lesions of the cord has been discussed, and the principles there laid down can be applied to cases of spinal tumor. It is necessary to repeat the warning that there are not infrequent instances in which the question can only be positively answered by an appeal to exploration, and that the gravity of the outlook justifies that measure in any doubtful case. Prognosis. — In the large majority of cases of vertebral tumors their malignant characters render the prognosis hopeless and the fatal termination a matter of months. With intravertebral growths the outlook depends entirely on the possibility of successful removal, the liability to recurrence and the condition of the spinal cord at the time the attempt to remove them is made. The prognosis must always be grave until these questions can be answered. The most favorable cases are those of localized benign or com- paratively benign tumors in the extradural or intradural spaces, and the least favorable those of diffuse or multiple extramedullary neoplasms and all those of intramedullary origin. It is fortunate that compression of the cord may be prolonged and severe without destroying all hope that its func- tional activity can be restored if the source of pressure is removed. Indica- tions as to the expectation of life in inoperable cases of spinal tumor have already been given in discussing their course and result. Treatment. — From the therapeutic point of view cases of spinal tumor may be divided into operable and inoperable classes. With those which are inoperable remedial measures must be directed toward the alleviation of pain and the prevention of complications, such as sepsis, bronchitis, CAVITIES AND FISSURES OF THE SPINAL CORD 213 pneumonia, cystitis, and pyonephritis. The alleviation of pain may be difficult, but less compunction need be felt about the administration of nar- cotics than in diseases with a more favorable outlook. Unfortunately the pain produced by pressure upon the afferent roots and the great discomfort evoked by flexor spasms of the lower limbs in the stage of advanced spastic paraplegia do not always yield even to opium. In this contingency the advisability of dividing the posterior roots for the relief of the more urgent sufferings may be well considered. The possibility of a syphilitic basis for the symptoms of spinal tumor, in the shape of an intramedullary gumma or a local gummatous meningitis, must not be forgotten, and antisyphilitic remedies should always be given a trial in doubtful cases. The examination of the spinal fluid should be resorted to for the purpose of setting these doubts at rest. A large number of cases of intravertebral tumor are suitable for surgical exploration, even if only a small proportion attain a really successful result. With our present knowledge it is usually possible to give an accurate diagnosis of the site of the lesion, but rarely possible to state the nature, size, origin or possibility of removal of the growth. Nothing short of exposure of the tumor can clear up these points, and there is less harm done by operating on cases of what prove to be ineradicable spinal neoplasms than by choosing un- suitable cases of intracranial growth for surgical intervention. An oppor- tunity is afforded for relieving pain even when the disease cannot be arrested, and the operation in skilled hands is attended by no undue risk considering the gravity of the case. The surgeon who can stay his hand when a laminec- tomy exposes a hopeless condition will do no harm even if he effects no good. This is not the place to discuss surgical details, but one or two points may be noted. It sometimes happens that on the removal of two or three laminae no tumor is found in the expected situation. The absence of pulsa- tion in the theca at this level should encourage the surgeon to go higher, and he will probably find the source of pressure by removing another arch or two. It is less common for the laminectomy to be performed at too high a level, but in such a case the healthy pulsation of the theca may suggest the advisability of extending the wound downward. The removal of several arches is not attended by the disastrous results in the way of lack of support which might be expected. The after treatment of successful operations is that of convalescing myelitis. The restoration of function in paralyzed limbs may be hastened by the employment of massage and electricity, but attention to the general nutrition and health of the patient will do the rest. CAVITIES AND FISSURES OF THE SPINAL CORD. Under this title are included a number of conditions of little practical importance with the exception of syringomyelia. For some reason we are accustomed to term "cavities" in the spinal cord what would, perhaps more properly, be termed "cysts" in other organs. At any rate we mean by a cavity a space, with or without an organized wall, containing fluid. Cavities, continuing the abuse of this term, are the not infrequent terminal results of an acute inflammation, in the course of which portions of the spinal tissue have become necrosed and ultimately absorbed. An example may be 214 DISEASES OF THE NERVOUS SYSTEM found in the cord of a long-standing case of poliomyelitis, just as a cyst or porencephaly may represent an old encephalitis. Of very similar origin are the cysts or cavities resulting from an old focal hemorrhage or thrombosis. These cavities have no definite lining membranes, their walls consisting of neuroglia which may or may not be compressed so as to give it a condensed laminated appearance. The term "fissure" is usually applied to a cavity which is narrow, and which may appear narrower after it has lost its fluid contents than it did before it was opened. Care must be taken not to regard as fissures those spaces which are seen in microscopic specimens as the result of hardening processes, and which are particularly liable to be artificially formed along the tracts of bloodvessels when the walls of the latter have been thickened by disease or when the embedding has not been skilfully carried out. Hydromyelia. — This name has been variously used, and it would cause less confusion if it were confined to cases of simple dilatation of the central canal without co-existing alterations in surrounding structures, apart from the results of simple stretching, and without clinical symptoms. The condi- tion is most frequently found in infants with congenital hydrocephalus, spina bifida, or other developmental abnormalities, but may also be present unsuspected in older persons in minor degrees. A satisfactory explanation of its production is difficult, but increase of fluid pressure due to mechanical causes, or physiological increase of fluid output by an overactive ependyma, may be of sufficient account in certain cases. The hydromyelic cavity is lined by ependymal cells, and its shape is usually round, but sometimes T-shaped, owing to a diverticulum in the direction of the posterior median septum. The addition of some peri-ependymal gliosis or of ependymal proliferation with the formation of accessory canals is the first step toward the production of what is termed "syringomyelia," and is evidence of the very imperfect line of demarcation separating the two conditions. Syringomyelia (<™/>po<;, ash-colored); regressive paralysis; essential paralysis of infants; French, poliomyelite anterieure aigue; German, Kinderlahmung spinale, essen- tielle Kinderlahmung; Italian, poliomielitide anteriore; Latin, polio- myelitis anterior acuta. The term "acute poliomyelitis" is chosen on account of its simplicity and because the additional word "anterior" is neither necessary nor strictly in accord with modern knowledge of the pathology. The use of the word "infantile" should be discouraged, because it suggests a children's disease distinct from that which affects adults — a distinction which has no scientific basis. The use of the term "essential" dates from the time when the condi- tion was supposed to have no characteristic anatomical lesions. Definition. — An acute, probably specific, febrile illness affecting children and young adults, characterized anatomically by a confluent or discrete inflammation of the gray matter of the spinal cord and brain stem, with resulting destruction of the nerve cells and consequent degeneration of their axis-cylinder processes and atrophy of muscles, and clinically by a rapid atrophic paralysis of various skeletal muscles, usually those of the limbs, but occasionally also those of the head and trunk, a paralysis which reaches its maximum in a few hours and tends toward recovery in some parts and to the production of permanent disabilities and deformities in others. History. — Heine, in 1840, was one of the first physicians to observe the disease and recognize that the spinal cord was the seat of the lesion. Three years later Colmer referred to an epidemic of "teething paralysis" identical with acute poliomyelitis in West Feliciana. Vogt and Duchenne, of Boulogne, described the disease in adults in 1858 and 1864 respectively. The first pathological researches were made by Cornil in 1863, and in 1865 Prevost and Vulpian examined a long-standing case in a woman aged seventy-eight ACUTE POLIOMYELITIS 259 years, and found degeneration of the anterior horn cells, with chronic inter- stitial changes in the surrounding tissue. Their view that the disease was due to a primary cell change was upheld by Lockhart Clarke, Charcot and Joffroy, and other observers, but an entirely new light was thrown upon the pathology by Roger and Damaschino, who published three cases of young children dying at intervals of two months, six months, and thirteen months after the onset of paralysis. The morbid changes found by these authors, and confirmed by Charlewood Turner, Frederick Taylor, Drummond, Rissler, Putnam, and others, gave rise to the opinion that a primary inflammatory pro- cess was the basis of the disease. As in many other diseases, the accumu- lated work of the last half century has produced the opinion that an infec- tive agent is responsible. Etiology. — Distribution. — Acute poliomyelitis is a disease of wide if not universal distribution, as it is known to occur on every continent. Judging from medical literature, it would seem that North America and Scandinavia suffer far more severely than many southern countries. Sex. — Among children the two sexes are about equally affected, but several observers, including Gowers, state that after adult age is reached, males are more frequently victims of the disease than females. Age. — The large majority of cases occur in the first five years, after which the liability diminishes progressively up to the third and fourth decade. The occurrence of acute poliomyelitis is almost unknown after forty years of age. The question of an intra-uterine attack is not settled, but the writer has seen (with Dr. F. E. Batten) an instance in which that diagnosis appeared to be justified. Duchenne described a case in an infant twelve days old, but the frequency of the disease, even if the possibility of fatal cases occurring and being overlooked is taken into account, does not reach its maximum until the second or third year of life. Taking the figures of Seeligmuller, Galbraith, Sinkler, Gowers, and Starr together, they show 121 in the first, 228 in the second, 158 in the third, 66 in the fourth, 46 in the fifth, and 16 in the sixth year of life. A similar age incidence is a prominent feature of the epidemics which have been recorded ; 85 of Caverley's 119 cases were under six years of age, and in Nannestad's epidemic of 41 cases, 24 had not completed their fifth year. Season. — Barlow and Sinkler were the first to point out the undoubted influence of season, and it is now generally agreed that in the hot summer months cases are much more common than at other times of the year. Out of 452 cases collected by Barlow, Sinkler, Gowers, and Starr, 369 had their onset in June, July, August, September, and October, and all the chief epidemics have been observed during the hot season. Both in America and England the months of July, August, and September claim the greatest prevalence, and in large cities some years seem to be more favorable to the development of the disease than others. Trauma. — Trauma has so long been regarded as a possible cause for many diseases of the nervous system that it attracts, if it does not deserve, some attention. There is no evidence that trauma can play any important role in this disease, although parents are very frequently able to remember some fall or blow preceding, more or less remotely, the onset. It is possible that a central hemorrhage may be produced by a severe trauma, and that the resulting symptoms may be those of an atrophic local paralysis, but if such gases exist they are not examples of acute poliomyelitis. Changes of tern- 260 DISEASES OF THE NERVOUS SYSTEM perature, prolonged bathing or paddling, may be predisposing causes, but the fact that the disease is more prevalent in hot weather should displace "chill" from the high pedestal it occupies in the lay mind as an exciting agent. The relationship of the specific fevers of childhood to acute poliomyelitis has been the subject of some attention, but there is obviously a danger of its gaining undue importance. It is generally agreed that the disease some- times follows, at varying intervals, measles, scarlet fever, diphtheria, and other fevers. There are, however, plenty of instances of one acute specific fever following quickly on another without any suggestion forthcoming that the later condition is a result of the earlier one. Moreover, Gowers is un- questionably right when he says, "The initial general disturbance is constantly mistaken for an independent general disease, and the opinion is often main- tained after the discovery of the paralysis, which is then supposed to be of secondary origin." Most observers will readily admit that the victims of acute poliomyelitis are, generally speaking, healthy if not robust children, on whom the para- lysis falls with particularly cruel and unexpected suddenness. There is no evidence to support the view that teething even favors the development of the disease beyond the fact that the period of the first dentition is also the period of life when acute poliomyelitis is most rife. Pathology. — The morbid changes which are present in the early days of the disease will be dealt with first. In this connection certain broad statements may be made: (1) The morbid anatomy of the epidemic cases is similar to that of the sporadic cases. (2) The changes in the adult are the same as those in the child. (3) In all cases the extent of the disease as shown by examination of the tissues is greater than could be inferred from the clinical symptoms. If, for instance, a patient dies from the effects of paralysis of the limbs and trunk muscles, it is safe to prophesy that ana- tomical evidence of the disease will be found also in the brain stem, and perhaps even in the cerebral and cerebellar hemispheres. To the naked eye the meninges covering the central nervous system are hyperaemic. The substance of the cord and brain, and particularly the gray matter, appears vascular, and the latter may, in the more severe cases, be hemorrhagic and softened. A section of the spinal cord stained with log- wood presents a striking appearance. The gray matter stands out unusually well on account of the numerous cells it contains, and all vessels, in both white and gray matter, are rendered prominent by their engorgement and by the dark staining of their perivascular sheaths. The histological anatomy may be discussed under the following heads: (1) Meninges, (2) White Matter, (3) Gray Matter, (4) Central Canal. 1. Meninges. — It is usual to find the vessels of the soft meninges full of blood, and in the more severe instances of the disease the membranes contain an excess of cells, chiefly lymphocytes, lying in the tissue meshes between the vessels. In many cases this cellular infiltration is only evident in the lumbosacral region, but in a few it extends to the higher parts of the cord and even to the basal meninges of the brain. It never gives rise to an appear- ance of pus to the naked eye, nor do the cells themselves resemble the leuko- cytes of that fluid. The amount of cellular infiltration is usually greater on the anterolateral than on the posterior surface of the cord. In the cases examined by the writer the majority of the cells in the pia arachnoid were of PLATE XIV - :^ c,J. ' . Section of the Spinal Cord in Acute Poliomyelitis. PLATE XV FIG. 1 • v. * . •„ .;*>.'• «. > . t/